--- a/accessible/atk/moz.build
+++ b/accessible/atk/moz.build
@@ -50,10 +50,8 @@ if CONFIG['MOZ_ENABLE_GTK']:
 if CONFIG['MOZ_ENABLE_DBUS']:
     CXXFLAGS += CONFIG['MOZ_DBUS_CFLAGS']
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 if CONFIG['CLANG_CXX']:
     # Suppress clang warning about unused function from gobject's RTTI macros.
     CXXFLAGS += ['-Wno-unused-function']
-
-FAIL_ON_WARNINGS = True

--- a/accessible/base/moz.build
+++ b/accessible/base/moz.build
@@ -92,10 +92,8 @@ else:
     ]
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['MOZ_ENABLE_GTK']:
     CXXFLAGS += CONFIG['MOZ_CAIRO_CFLAGS']
 
 include('/ipc/chromium/chromium-config.mozbuild')
-
-FAIL_ON_WARNINGS = True

--- a/accessible/generic/moz.build
+++ b/accessible/generic/moz.build
@@ -52,10 +52,8 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'co
 else:
     LOCAL_INCLUDES += [
         '/accessible/other',
     ]
 
 FINAL_LIBRARY = 'xul'
 
 include('/ipc/chromium/chromium-config.mozbuild')
-
-FAIL_ON_WARNINGS = True

--- a/accessible/html/moz.build
+++ b/accessible/html/moz.build
@@ -38,10 +38,8 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'co
         '/accessible/mac',
     ]
 else:
     LOCAL_INCLUDES += [
         '/accessible/other',
     ]
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/accessible/ipc/moz.build
+++ b/accessible/ipc/moz.build
@@ -42,10 +42,8 @@ if CONFIG['ACCESSIBILITY']:
     else:
         LOCAL_INCLUDES += [
             '/accessible/other',
         ]
 
     FINAL_LIBRARY = 'xul'
 
 include('/ipc/chromium/chromium-config.mozbuild')
-
-FAIL_ON_WARNINGS = True

--- a/accessible/mac/moz.build
+++ b/accessible/mac/moz.build
@@ -36,10 +36,8 @@ LOCAL_INCLUDES += [
     '/layout/xul',
     '/widget',
     '/widget/cocoa',
 ]
 
 FINAL_LIBRARY = 'xul'
 
 include('/ipc/chromium/chromium-config.mozbuild')
-
-FAIL_ON_WARNINGS = True

--- a/accessible/other/moz.build
+++ b/accessible/other/moz.build
@@ -17,10 +17,8 @@ SOURCES += [
 LOCAL_INCLUDES += [
     '/accessible/base',
     '/accessible/generic',
     '/accessible/html',
     '/accessible/xul',
 ]
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/accessible/windows/ia2/moz.build
+++ b/accessible/windows/ia2/moz.build
@@ -45,11 +45,9 @@ LOCAL_INCLUDES += [
     '/accessible/xul',
 ]
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')

--- a/accessible/windows/msaa/moz.build
+++ b/accessible/windows/msaa/moz.build
@@ -59,10 +59,8 @@ LOCAL_INCLUDES += [
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
-
-FAIL_ON_WARNINGS = True

--- a/accessible/windows/sdn/moz.build
+++ b/accessible/windows/sdn/moz.build
@@ -18,10 +18,8 @@ LOCAL_INCLUDES += [
     '/accessible/xpcom',
     '/accessible/xul',
 ]
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
-
-FAIL_ON_WARNINGS = True

--- a/accessible/windows/uia/moz.build
+++ b/accessible/windows/uia/moz.build
@@ -13,10 +13,8 @@ LOCAL_INCLUDES += [
     '/accessible/generic',
     '/accessible/html',
     '/accessible/windows/msaa',
     '/accessible/xpcom',
     '/accessible/xul',
 ]
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/accessible/xpcom/moz.build
+++ b/accessible/xpcom/moz.build
@@ -43,10 +43,10 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'co
     ]
 else:
     LOCAL_INCLUDES += [
         '/accessible/other',
     ]
 
 FINAL_LIBRARY = 'xul'
 
-if CONFIG['GNU_CXX']:
-    FAIL_ON_WARNINGS = True
+if not CONFIG['GNU_CXX']:
+    ALLOW_COMPILER_WARNINGS = True

--- a/accessible/xul/moz.build
+++ b/accessible/xul/moz.build
@@ -43,10 +43,8 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'co
         '/accessible/mac',
     ]
 else:
     LOCAL_INCLUDES += [
         '/accessible/other',
     ]
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/b2g/app/moz.build
+++ b/b2g/app/moz.build
@@ -73,17 +73,15 @@ DISABLE_STL_WRAPPING = True
 if CONFIG['OS_ARCH'] == 'WINNT':
     OS_LIBS += [
         'version',
     ]
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
 
-FAIL_ON_WARNINGS = True
-
 JS_PREFERENCE_FILES += [
     'b2g.js',
 ]
 
 DIST_FILES += [
   'ua-update.json.in',
 ]

--- a/b2g/config/mozconfigs/linux32_gecko/debug
+++ b/b2g/config/mozconfigs/linux32_gecko/debug
@@ -14,17 +14,17 @@ ac_add_options --enable-debug
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Use sccache
 no_sccache=
 
 #B2G options
 ac_add_options --enable-application=b2g
 ENABLE_MARIONETTE=1

--- a/b2g/config/mozconfigs/linux32_gecko/nightly
+++ b/b2g/config/mozconfigs/linux32_gecko/nightly
@@ -14,17 +14,17 @@ ac_add_options --enable-signmar
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Use sccache
 no_sccache=
 
 #B2G options
 ac_add_options --enable-application=b2g
 export CXXFLAGS=-DMOZ_ENABLE_JS_DUMP

--- a/b2g/config/mozconfigs/linux64_gecko/debug
+++ b/b2g/config/mozconfigs/linux64_gecko/debug
@@ -14,17 +14,17 @@ ac_add_options --enable-debug
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Use sccache
 no_sccache=
 
 #B2G options
 ac_add_options --enable-application=b2g
 ENABLE_MARIONETTE=1

--- a/b2g/config/mozconfigs/linux64_gecko/nightly
+++ b/b2g/config/mozconfigs/linux64_gecko/nightly
@@ -14,17 +14,17 @@ ac_add_options --enable-signmar
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Use sccache
 no_sccache=
 
 #B2G options
 ac_add_options --enable-application=b2g
 export CXXFLAGS=-DMOZ_ENABLE_JS_DUMP

--- a/b2g/config/mozconfigs/macosx64_gecko/debug
+++ b/b2g/config/mozconfigs/macosx64_gecko/debug
@@ -13,17 +13,17 @@ ac_add_options --enable-signmar
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
 #ac_add_options --with-macbundlename-prefix=Firefox
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # B2G Stuff
 ac_add_options --enable-application=b2g
 ac_add_options --enable-debug-symbols
 ac_add_options --enable-debug
 ENABLE_MARIONETTE=1
 

--- a/b2g/config/mozconfigs/macosx64_gecko/nightly
+++ b/b2g/config/mozconfigs/macosx64_gecko/nightly
@@ -14,17 +14,17 @@ ac_add_options --enable-signmar
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
 #ac_add_options --with-macbundlename-prefix=Firefox
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # B2G Stuff
 ac_add_options --enable-application=b2g
 ac_add_options --enable-debug-symbols
 export CXXFLAGS=-DMOZ_ENABLE_JS_DUMP
 
 GAIADIR=$topsrcdir/gaia

--- a/b2g/dev/config/mozconfigs/macosx64/mulet
+++ b/b2g/dev/config/mozconfigs/macosx64/mulet
@@ -12,17 +12,17 @@ ac_add_options --enable-profiling
 ac_add_options --enable-instruments
 ac_add_options --enable-dtrace
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 ac_add_options --with-macbundlename-prefix=Firefox
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 # Include Firefox OS fonts.
 MOZTTDIR=$topsrcdir/moz-tt
 

--- a/b2g/gaia/moz.build
+++ b/b2g/gaia/moz.build
@@ -15,10 +15,8 @@ if not CONFIG['MOZ_B2GDROID']:
         DEFINES['B2G_NAME'] = 'L"%s-bin%s"' % (PROGRAM, CONFIG['BIN_SUFFIX'])
         DEFINES['GAIA_PATH'] = 'L"gaia\\\\profile"'
     else:
         SOURCES += [
             'run-b2g.c',
         ]
         DEFINES['B2G_NAME'] = '"%s-bin%s"' % (PROGRAM, CONFIG['BIN_SUFFIX'])
         DEFINES['GAIA_PATH'] = '"gaia/profile"'
-
-FAIL_ON_WARNINGS = True

--- a/browser/app/moz.build
+++ b/browser/app/moz.build
@@ -81,10 +81,8 @@ if CONFIG['MOZ_LINKER']:
 
 if CONFIG['HAVE_CLOCK_MONOTONIC']:
     OS_LIBS += CONFIG['REALTIME_LIBS']
 
 JAR_MANIFESTS += ['jar.mn']
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
-
-FAIL_ON_WARNINGS = True

--- a/browser/components/about/moz.build
+++ b/browser/components/about/moz.build
@@ -12,10 +12,8 @@ SOURCES += [
     'AboutRedirector.cpp',
 ]
 
 FINAL_LIBRARY = 'browsercomps'
 
 LOCAL_INCLUDES += [
     '../build',
 ]
-
-FAIL_ON_WARNINGS = True

--- a/browser/components/build/moz.build
+++ b/browser/components/build/moz.build
@@ -33,10 +33,8 @@ if CONFIG['OS_ARCH'] == 'WINNT':
     DELAYLOAD_DLLS += [
         'esent.dll',
     ]
 
 # Mac: Need to link with CoreFoundation for Mac Migrators (PList reading code)
 # GTK2: Need to link with glib for GNOME shell service
 if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('cocoa', 'gtk2', 'gtk3'):
     OS_LIBS += CONFIG['TK_LIBS']
-
-FAIL_ON_WARNINGS = True

--- a/browser/components/dirprovider/moz.build
+++ b/browser/components/dirprovider/moz.build
@@ -16,10 +16,8 @@ XPCSHELL_TESTS_MANIFESTS += [
     'tests/unit/xpcshell.ini',
 ]
 
 FINAL_LIBRARY = 'browsercomps'
 
 LOCAL_INCLUDES += [
     '../build'
 ]
-
-FAIL_ON_WARNINGS = True

--- a/browser/components/feeds/moz.build
+++ b/browser/components/feeds/moz.build
@@ -35,12 +35,10 @@ FINAL_LIBRARY = 'browsercomps'
 
 for var in ('MOZ_APP_NAME', 'MOZ_MACBUNDLE_NAME'):
     DEFINES[var] = CONFIG[var]
 
 LOCAL_INCLUDES += [
     '../build',
 ]
 
-FAIL_ON_WARNINGS = True
-
 with Files('**'):
     BUG_COMPONENT = ('Firefox', 'RSS Discovery and Preview')

--- a/browser/components/migration/moz.build
+++ b/browser/components/migration/moz.build
@@ -59,12 +59,10 @@ EXTRA_PP_JS_MODULES += [
 
 if CONFIG['OS_ARCH'] == 'WINNT':
     EXTRA_JS_MODULES += [
         'MSMigrationUtils.jsm',
     ]
 
 FINAL_LIBRARY = 'browsercomps'
 
-FAIL_ON_WARNINGS = True
-
 with Files('**'):
     BUG_COMPONENT = ('Firefox', 'Migration')

--- a/browser/components/shell/moz.build
+++ b/browser/components/shell/moz.build
@@ -45,12 +45,10 @@ EXTRA_COMPONENTS += [
     'nsSetDefaultBrowser.manifest',
 ]
 
 for var in ('MOZ_APP_NAME', 'MOZ_APP_VERSION'):
     DEFINES[var] = '"%s"' % CONFIG[var]
 
 CXXFLAGS += CONFIG['TK_CFLAGS']
 
-FAIL_ON_WARNINGS = True
-
 with Files('**'):
     BUG_COMPONENT = ('Firefox', 'Shell Integration')

--- a/browser/config/mozconfigs/linux32/common-opt
+++ b/browser/config/mozconfigs/linux32/common-opt
@@ -8,13 +8,13 @@ ac_add_options --with-mozilla-api-keyfil
 
 . $topsrcdir/build/unix/mozconfig.linux32
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1

--- a/browser/config/mozconfigs/linux32/debug
+++ b/browser/config/mozconfigs/linux32/debug
@@ -7,17 +7,17 @@ MOZ_AUTOMATION_L10N_CHECK=0
 
 . $topsrcdir/build/unix/mozconfig.linux32
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 #Use ccache
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"

--- a/browser/config/mozconfigs/linux64/common-opt
+++ b/browser/config/mozconfigs/linux64/common-opt
@@ -8,13 +8,13 @@ ac_add_options --with-mozilla-api-keyfil
 
 . $topsrcdir/build/unix/mozconfig.linux
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1

--- a/browser/config/mozconfigs/linux64/debug
+++ b/browser/config/mozconfigs/linux64/debug
@@ -5,17 +5,17 @@ ac_add_options --with-google-oauth-api-k
 
 MOZ_AUTOMATION_L10N_CHECK=0
 
 . $topsrcdir/build/unix/mozconfig.linux
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"

--- a/browser/config/mozconfigs/macosx-universal/common-opt
+++ b/browser/config/mozconfigs/macosx-universal/common-opt
@@ -11,13 +11,13 @@ ac_add_options --with-google-api-keyfile
 ac_add_options --with-google-oauth-api-keyfile=/builds/google-oauth-api.key
 ac_add_options --with-mozilla-api-keyfile=/builds/mozilla-desktop-geoloc-api.key
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1

--- a/browser/config/mozconfigs/macosx64/debug
+++ b/browser/config/mozconfigs/macosx64/debug
@@ -7,17 +7,17 @@ ac_add_options --with-google-oauth-api-k
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 if test "${MOZ_UPDATE_CHANNEL}" = "nightly"; then
 ac_add_options --with-macbundlename-prefix=Firefox
 fi
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/macosx/mozconfig.rust"

--- a/browser/config/mozconfigs/macosx64/debug-static-analysis
+++ b/browser/config/mozconfigs/macosx64/debug-static-analysis
@@ -2,15 +2,15 @@ MOZ_AUTOMATION_BUILD_SYMBOLS=0
 MOZ_AUTOMATION_PACKAGE_TESTS=0
 MOZ_AUTOMATION_L10N_CHECK=0
 
 . $topsrcdir/build/macosx/mozconfig.common
 
 ac_add_options --enable-debug
 ac_add_options --enable-dmd
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 ac_add_options --enable-clang-plugin
 
 . "$topsrcdir/build/mozconfig.common.override"
 . "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/macosx64/nightly
+++ b/browser/config/mozconfigs/macosx64/nightly
@@ -5,17 +5,17 @@ ac_add_options --with-google-oauth-api-k
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 if test "${MOZ_UPDATE_CHANNEL}" = "nightly"; then
 ac_add_options --with-macbundlename-prefix=Firefox
 fi
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/macosx/mozconfig.rust"

--- a/browser/config/mozconfigs/win32/common-opt
+++ b/browser/config/mozconfigs/win32/common-opt
@@ -24,17 +24,17 @@ ac_add_options --with-mozilla-api-keyfil
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
 . $topsrcdir/build/win32/mozconfig.vs2013-win64
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Enable Adobe Primetime CDM on 32-bit Windows in Mozilla builds.
 # Enabled here on the assumption that downstream vendors will not be using
 # these build configs.
 ac_add_options --enable-eme=adobe
 
 # Package js shell.

--- a/browser/config/mozconfigs/win32/debug
+++ b/browser/config/mozconfigs/win32/debug
@@ -15,17 +15,17 @@ else
 fi
 ac_add_options --with-google-oauth-api-keyfile=${_google_oauth_api_keyfile}
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 . $topsrcdir/build/win32/mozconfig.vs2013-win64
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . "$topsrcdir/build/mozconfig.common.override"

--- a/browser/config/mozconfigs/win64/common-opt
+++ b/browser/config/mozconfigs/win64/common-opt
@@ -20,15 +20,15 @@ fi
 ac_add_options --with-google-oauth-api-keyfile=${_google_oauth_api_keyfile}
 ac_add_options --with-mozilla-api-keyfile=/c/builds/mozilla-desktop-geoloc-api.key
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
 export MOZ_TELEMETRY_REPORTING=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 . $topsrcdir/build/win64/mozconfig.vs2013
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1

--- a/browser/config/mozconfigs/win64/debug
+++ b/browser/config/mozconfigs/win64/debug
@@ -15,17 +15,17 @@ if [ -f /c/builds/google-oauth-api.key ]
 else
   _google_oauth_api_keyfile=/e/builds/google-oauth-api.key
 fi
 ac_add_options --with-google-oauth-api-keyfile=${_google_oauth_api_keyfile}
 
 # Needed to enable breakpad in application.ini
 export MOZILLA_OFFICIAL=1
 
-# Treat warnings as errors in directories with FAIL_ON_WARNINGS.
+# Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
 . $topsrcdir/build/win64/mozconfig.vs2013

--- a/build/mobile/sutagent/android/fencp/DirCursor.java
+++ b/build/mobile/sutagent/android/fencp/DirCursor.java
@@ -43,19 +43,16 @@ public class DirCursor extends MatrixCur
     private void doLoadCursor(String sDir) {
         File dir = new File(sDir);
         int    nFiles = 0;
         int nCols = theColumns.length;
         int    lcvFiles = 0;
         int    nCIndex = 0;
         Object [] vals = new Object[nCols];
         
-        if (vals == null)
-            return;
-        
         if (dir.isDirectory()) {
             try {
                 nCIndex = getColumnIndex(_ID);
                 if (nCIndex > -1)
                     vals[nCIndex] = -1;
 
                 nCIndex = getColumnIndex(ISDIR);
                 if (nCIndex > -1)

--- a/build/mobile/sutagent/android/ffxcp/DirCursor.java
+++ b/build/mobile/sutagent/android/ffxcp/DirCursor.java
@@ -43,19 +43,16 @@ public class DirCursor extends MatrixCur
     private void doLoadCursor(String sDir) {
         File dir = new File(sDir);
         int    nFiles = 0;
         int nCols = theColumns.length;
         int    lcvFiles = 0;
         int    nCIndex = 0;
         Object [] vals = new Object[nCols];
 
-        if (vals == null)
-            return;
-
         if (dir.isDirectory()) {
             try {
                 nCIndex = getColumnIndex(_ID);
                 if (nCIndex > -1)
                     vals[nCIndex] = -1;
 
                 nCIndex = getColumnIndex(ISDIR);
                 if (nCIndex > -1)

--- a/build/stlport/moz.build
+++ b/build/stlport/moz.build
@@ -64,8 +64,10 @@ if CONFIG['GNU_CXX']:
         '-Wno-empty-body',
         '-Wno-type-limits',
         '-Wno-unused-local-typedefs',
     ]
 
 # Force to build a static library, instead of a fake library, without
 # installing it in dist/lib.
 NO_EXPAND_LIBS = True
+
+ALLOW_COMPILER_WARNINGS = True

--- a/caps/moz.build
+++ b/caps/moz.build
@@ -46,10 +46,8 @@ UNIFIED_SOURCES += [
 LOCAL_INCLUDES += [
     '/dom/base',
     '/js/xpconnect/src',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/chrome/moz.build
+++ b/chrome/moz.build
@@ -35,10 +35,8 @@ GENERATED_INCLUDES += [
 LOCAL_INCLUDES += [
     '/netwerk/base',
     '/netwerk/protocol/res',
     '/xpcom/components'
 ]
 
 if CONFIG['MOZ_ENABLE_GTK']:
     CXXFLAGS += CONFIG['TK_CFLAGS']
-
-FAIL_ON_WARNINGS = True

--- a/config/config.mk
+++ b/config/config.mk
@@ -354,35 +354,37 @@ else
 HOST_CFLAGS	+= $(MOZ_OPTIMIZE_FLAGS)
 endif # MOZ_OPTIMIZE == 1
 endif # MOZ_OPTIMIZE
 endif # CROSS_COMPILE
 
 CFLAGS += $(MOZ_FRAMEPTR_FLAGS)
 CXXFLAGS += $(MOZ_FRAMEPTR_FLAGS)
 
-# Check for FAIL_ON_WARNINGS (Shorthand for Makefiles to request that we use
-# the 'warnings as errors' compile flags)
+# Check for ALLOW_COMPILER_WARNINGS (shorthand for Makefiles to request that we
+# *don't* use the warnings-as-errors compile flags)
 
-# NOTE: First, we clear FAIL_ON_WARNINGS[_DEBUG] if we're doing a Windows PGO
-# build, since WARNINGS_AS_ERRORS has been suspected of causing isuses in that
-# situation. (See bug 437002.)
+# Don't use warnings-as-errors in Windows PGO builds because it is suspected of
+# causing problems in that situation. (See bug 437002.)
 ifeq (WINNT_1,$(OS_ARCH)_$(MOZ_PROFILE_GENERATE)$(MOZ_PROFILE_USE))
-FAIL_ON_WARNINGS=
+ALLOW_COMPILER_WARNINGS=1
 endif # WINNT && (MOS_PROFILE_GENERATE ^ MOZ_PROFILE_USE)
 
-# Check for normal version of flag, and add WARNINGS_AS_ERRORS if it's set to 1.
-ifdef FAIL_ON_WARNINGS
-# Never treat warnings as errors in clang-cl, because it warns about many more
+# Don't use warnings-as-errors in clang-cl because it warns about many more
 # things than MSVC does.
-ifndef CLANG_CL
+ifdef CLANG_CL
+ALLOW_COMPILER_WARNINGS=1
+endif # CLANG_CL
+
+# Use warnings-as-errors if ALLOW_COMPILER_WARNINGS is not set to 1 (which
+# includes the case where it's undefined).
+ifneq (1,$(ALLOW_COMPILER_WARNINGS))
 CXXFLAGS += $(WARNINGS_AS_ERRORS)
 CFLAGS   += $(WARNINGS_AS_ERRORS)
-endif # CLANG_CL
-endif # FAIL_ON_WARNINGS
+endif # ALLOW_COMPILER_WARNINGS
 
 ifeq ($(OS_ARCH)_$(GNU_CC),WINNT_)
 #// Currently, unless USE_STATIC_LIBS is defined, the multithreaded
 #// DLL version of the RTL is used...
 #//
 #//------------------------------------------------------------------------
 ifdef USE_STATIC_LIBS
 RTL_FLAGS=-MT          # Statically linked multithreaded RTL

--- a/config/external/nss/moz.build
+++ b/config/external/nss/moz.build
@@ -40,8 +40,11 @@ else:
     Library('nss')
     USE_LIBS += [
         '/security/nss/lib/nss/nss3',
         '/security/nss/lib/smime/smime3',
         '/security/nss/lib/ssl/ssl3',
         '/security/nss/lib/util/nssutil3',
         'sqlite',
     ]
+
+# XXX: We should fix these warnings.
+ALLOW_COMPILER_WARNINGS = True

--- a/config/moz.build
+++ b/config/moz.build
@@ -37,8 +37,11 @@ PYTHON_UNIT_TESTS += [
     'tests/unit-expandlibs.py',
     'tests/unit-mozunit.py',
     'tests/unit-nsinstall.py',
     'tests/unit-printprereleasesuffix.py',
 ]
 
 if CONFIG['GNU_CC'] and CONFIG['MOZ_OPTIMIZE']:
     CFLAGS += ['-O3']
+
+# XXX: We should fix these warnings.
+ALLOW_COMPILER_WARNINGS = True

--- a/db/sqlite3/src/moz.build
+++ b/db/sqlite3/src/moz.build
@@ -4,16 +4,18 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 NO_VISIBILITY_FLAGS = True
 
 EXPORTS += [
     'sqlite3.h',
 ]
 
+ALLOW_COMPILER_WARNINGS = True
+
 if CONFIG['MOZ_FOLD_LIBS']:
     # When folding libraries, sqlite is actually in the nss library.
     FINAL_LIBRARY = 'nss'
 else:
     # The final library is in config/external/sqlite
     FINAL_LIBRARY = 'sqlite'
 
 SOURCES += [

--- a/docshell/base/moz.build
+++ b/docshell/base/moz.build
@@ -60,18 +60,16 @@ UNIFIED_SOURCES += [
     'nsDocShellLoadInfo.cpp',
     'nsDocShellTransferableHooks.cpp',
     'nsDownloadHistory.cpp',
     'nsDSURIContentListener.cpp',
     'nsWebNavigationInfo.cpp',
     'SerializedLoadContext.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/docshell/shistory',
     '/dom/base',
     '/layout/base',
     '/layout/generic',

--- a/docshell/base/timeline/moz.build
+++ b/docshell/base/timeline/moz.build
@@ -22,15 +22,13 @@ EXPORTS.mozilla += [
 UNIFIED_SOURCES += [
     'AutoGlobalTimelineMarker.cpp',
     'AutoTimelineMarker.cpp',
     'ObservedDocShell.cpp',
     'TimelineConsumers.cpp',
     'TimelineMarker.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/docshell/base'
 ]

--- a/docshell/build/moz.build
+++ b/docshell/build/moz.build
@@ -22,10 +22,8 @@ LOCAL_INCLUDES += [
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
     LOCAL_INCLUDES += ['/uriloader/exthandler/mac']
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
-
-FAIL_ON_WARNINGS = True

--- a/docshell/shistory/moz.build
+++ b/docshell/shistory/moz.build
@@ -22,15 +22,13 @@ EXPORTS += [
 
 UNIFIED_SOURCES += [
     'nsSHEntry.cpp',
     'nsSHEntryShared.cpp',
     'nsSHistory.cpp',
     'nsSHTransaction.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '/docshell/base',
 ]
 
 FINAL_LIBRARY = 'xul'

--- a/dom/activities/moz.build
+++ b/dom/activities/moz.build
@@ -26,17 +26,15 @@ EXTRA_COMPONENTS += [
     'ActivityWrapper.js',
 ]
 
 EXTRA_JS_MODULES += [
     'ActivitiesService.jsm',
     'ActivitiesServiceFilter.jsm',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

--- a/dom/alarm/moz.build
+++ b/dom/alarm/moz.build
@@ -23,17 +23,15 @@ EXTRA_COMPONENTS += [
     'AlarmsManager.manifest',
 ]
 
 EXTRA_JS_MODULES += [
     'AlarmDB.jsm',
     'AlarmService.jsm',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 MOCHITEST_MANIFESTS += ['test/mochitest.ini']
 
 XPCSHELL_TESTS_MANIFESTS += ['test/xpcshell.ini']

--- a/dom/animation/Animation.cpp
+++ b/dom/animation/Animation.cpp
@@ -569,17 +569,18 @@ Animation::ComposeStyle(nsRefPtr<AnimVal
                         bool& aNeedsRefreshes)
 {
   if (!mEffect) {
     return;
   }
 
   AnimationPlayState playState = PlayState();
   if (playState == AnimationPlayState::Running ||
-      playState == AnimationPlayState::Pending) {
+      playState == AnimationPlayState::Pending ||
+      HasEndEventToQueue()) {
     aNeedsRefreshes = true;
   }
 
   if (!IsInEffect()) {
     return;
   }
 
   // In order to prevent flicker, there are a few cases where we want to use

--- a/dom/animation/Animation.h
+++ b/dom/animation/Animation.h
@@ -293,16 +293,29 @@ public:
    * |aNeedsRefreshes| will be set to true if this animation expects to update
    * the style rule on the next refresh driver tick as well (because it
    * is running and has an effect to sample).
    */
   void ComposeStyle(nsRefPtr<AnimValuesStyleRule>& aStyleRule,
                     nsCSSPropertySet& aSetProperties,
                     bool& aNeedsRefreshes);
 
+
+  // FIXME: Because we currently determine if we need refresh driver ticks
+  // during restyling (specifically ComposeStyle above) and not necessarily
+  // during a refresh driver tick, we can arrive at a situation where we
+  // have finished running an animation but are waiting until the next tick
+  // to queue the final end event. This method tells us when we are in that
+  // situation so we can avoid unregistering from the refresh driver until
+  // we've finished dispatching events.
+  //
+  // This is a temporary measure until bug 1195180 is done and we can do all
+  // our registering and unregistering within a tick callback.
+  virtual bool HasEndEventToQueue() const { return false; }
+
   void NotifyEffectTimingUpdated();
 
 protected:
   void SilentlySetCurrentTime(const TimeDuration& aNewCurrentTime);
   void SilentlySetPlaybackRate(double aPlaybackRate);
   void DoCancel();
   void DoPlay(ErrorResult& aRv, LimitBehavior aLimitBehavior);
   void DoPause(ErrorResult& aRv);

--- a/dom/animation/moz.build
+++ b/dom/animation/moz.build
@@ -25,11 +25,9 @@ UNIFIED_SOURCES += [
     'Animation.cpp',
     'AnimationEffectReadOnly.cpp',
     'AnimationTimeline.cpp',
     'DocumentTimeline.cpp',
     'KeyframeEffect.cpp',
     'PendingAnimationTracker.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'

--- a/dom/apps/moz.build
+++ b/dom/apps/moz.build
@@ -49,15 +49,13 @@ EXTRA_PP_JS_MODULES += [
     'OperatorApps.jsm',
     'ScriptPreloader.jsm',
     'Webapps.jsm',
 ]
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/js/xpconnect/wrappers',
 ]

--- a/dom/archivereader/moz.build
+++ b/dom/archivereader/moz.build
@@ -19,17 +19,15 @@ UNIFIED_SOURCES += [
     'ArchiveRequest.cpp',
     'ArchiveZipEvent.cpp',
     'ArchiveZipFile.cpp',
 ]
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '../base',
 ]
 
 FINAL_LIBRARY = 'xul'
 
 MOCHITEST_MANIFESTS += ['test/mochitest.ini']

--- a/dom/asmjscache/moz.build
+++ b/dom/asmjscache/moz.build
@@ -11,15 +11,13 @@ EXPORTS.mozilla.dom.asmjscache += [
 SOURCES += [
     'AsmJSCache.cpp'
 ]
 
 IPDL_SOURCES += [
     'PAsmJSCacheEntry.ipdl'
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 MOCHITEST_MANIFESTS += ['test/mochitest.ini']

--- a/dom/audiochannel/AudioChannelService.cpp
+++ b/dom/audiochannel/AudioChannelService.cpp
@@ -156,25 +156,30 @@ static const nsAttrValue::EnumTable kMoz
   { "notification",       (int16_t)AudioChannel::Notification },
   { "alarm",              (int16_t)AudioChannel::Alarm },
   { "telephony",          (int16_t)AudioChannel::Telephony },
   { "ringer",             (int16_t)AudioChannel::Ringer },
   { "publicnotification", (int16_t)AudioChannel::Publicnotification },
   { nullptr }
 };
 
-/* static */ already_AddRefed<AudioChannelService>
-AudioChannelService::GetOrCreate()
+/* static */ void
+AudioChannelService::CreateServiceIfNeeded()
 {
   MOZ_ASSERT(NS_IsMainThread());
 
   if (!gAudioChannelService) {
     gAudioChannelService = new AudioChannelService();
   }
+}
 
+/* static */ already_AddRefed<AudioChannelService>
+AudioChannelService::GetOrCreate()
+{
+  CreateServiceIfNeeded();
   nsRefPtr<AudioChannelService> service = gAudioChannelService.get();
   return service.forget();
 }
 
 void
 AudioChannelService::Shutdown()
 {
   if (gAudioChannelService) {
@@ -914,10 +919,11 @@ AudioChannelService::ChildStatusReceived
 
   data->mActiveTelephonyChannel = aTelephonyChannel;
   data->mActiveContentOrNormalChannel = aContentOrNormalChannel;
 }
 
 /* static */ bool
 AudioChannelService::IsAudioChannelMutedByDefault()
 {
+  CreateServiceIfNeeded();
   return sAudioChannelMutedByDefault;
 }

--- a/dom/audiochannel/AudioChannelService.h
+++ b/dom/audiochannel/AudioChannelService.h
@@ -137,16 +137,18 @@ public:
 
   void ChildStatusReceived(uint64_t aChildID, bool aTelephonyChannel,
                            bool aContentOrNormalChannel, bool aAnyChannel);
 
 private:
   AudioChannelService();
   ~AudioChannelService();
 
+  static void CreateServiceIfNeeded();
+
   /**
    * Shutdown the singleton.
    */
   static void Shutdown();
 
   void MaybeSendStatusUpdate();
 
   bool ContentOrNormalChannelIsActive();

--- a/dom/audiochannel/moz.build
+++ b/dom/audiochannel/moz.build
@@ -16,13 +16,11 @@ EXPORTS += [
     'AudioChannelService.h',
 ]
 
 UNIFIED_SOURCES += [
     'AudioChannelAgent.cpp',
     'AudioChannelService.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

--- a/dom/base/moz.build
+++ b/dom/base/moz.build
@@ -404,18 +404,16 @@ if CONFIG['MOZ_BUILD_APP'] != 'mobile/an
         'SiteSpecificUserAgent.manifest',
     ]
 
 EXTRA_JS_MODULES += [
     'DOMRequestHelper.jsm',
     'IndexedDBHelper.jsm',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '../battery',
     '../bluetooth/common',
     '../bluetooth/common/webapi',
     '../events',
     '../media',
     '../network',
     '../time',

--- a/dom/base/nsDOMMutationObserver.cpp
+++ b/dom/base/nsDOMMutationObserver.cpp
@@ -361,29 +361,28 @@ nsAnimationReceiver::RecordAnimationMuta
   }
 
   if (!Animations() || !(Subtree() || animationTarget == Target()) ||
       animationTarget->ChromeOnlyAccess()) {
     return;
   }
 
   if (nsAutoAnimationMutationBatch::IsBatching()) {
-    if (nsAutoAnimationMutationBatch::GetBatchTarget() != animationTarget) {
-      return;
-    }
-
     switch (aMutationType) {
       case eAnimationMutation_Added:
-        nsAutoAnimationMutationBatch::AnimationAdded(aAnimation);
+        nsAutoAnimationMutationBatch::AnimationAdded(aAnimation,
+                                                     animationTarget);
         break;
       case eAnimationMutation_Changed:
-        nsAutoAnimationMutationBatch::AnimationChanged(aAnimation);
+        nsAutoAnimationMutationBatch::AnimationChanged(aAnimation,
+                                                       animationTarget);
         break;
       case eAnimationMutation_Removed:
-        nsAutoAnimationMutationBatch::AnimationRemoved(aAnimation);
+        nsAutoAnimationMutationBatch::AnimationRemoved(aAnimation,
+                                                       animationTarget);
         break;
     }
 
     nsAutoAnimationMutationBatch::AddObserver(Observer());
     return;
   }
 
   nsDOMMutationRecord* m =
@@ -1054,39 +1053,53 @@ nsAutoAnimationMutationBatch::sCurrentBa
 
 void
 nsAutoAnimationMutationBatch::Done()
 {
   if (sCurrentBatch != this) {
     return;
   }
 
-  sCurrentBatch = mPreviousBatch;
+  sCurrentBatch = nullptr;
   if (mObservers.IsEmpty()) {
     nsDOMMutationObserver::LeaveMutationHandling();
     // Nothing to do.
     return;
   }
 
+  mBatchTargets.Sort(TreeOrderComparator());
+
   for (nsDOMMutationObserver* ob : mObservers) {
-    nsRefPtr<nsDOMMutationRecord> m =
-      new nsDOMMutationRecord(nsGkAtoms::animations, ob->GetParentObject());
-    m->mTarget = mBatchTarget;
+    bool didAddRecords = false;
+
+    for (nsINode* target : mBatchTargets) {
+      EntryArray* entries = mEntryTable.Get(target);
+      MOZ_ASSERT(entries,
+        "Targets in entry table and targets list should match");
+
+      nsRefPtr<nsDOMMutationRecord> m =
+        new nsDOMMutationRecord(nsGkAtoms::animations, ob->GetParentObject());
+      m->mTarget = target;
 
-    for (const Entry& e : mEntries) {
-      if (e.mState == eState_Added) {
-        m->mAddedAnimations.AppendElement(e.mAnimation);
-      } else if (e.mState == eState_Removed) {
-        m->mRemovedAnimations.AppendElement(e.mAnimation);
-      } else if (e.mState == eState_RemainedPresent && e.mChanged) {
-        m->mChangedAnimations.AppendElement(e.mAnimation);
+      for (const Entry& e : *entries) {
+        if (e.mState == eState_Added) {
+          m->mAddedAnimations.AppendElement(e.mAnimation);
+        } else if (e.mState == eState_Removed) {
+          m->mRemovedAnimations.AppendElement(e.mAnimation);
+        } else if (e.mState == eState_RemainedPresent && e.mChanged) {
+          m->mChangedAnimations.AppendElement(e.mAnimation);
+        }
+      }
+
+      if (!m->mAddedAnimations.IsEmpty() ||
+          !m->mChangedAnimations.IsEmpty() ||
+          !m->mRemovedAnimations.IsEmpty()) {
+        ob->AppendMutationRecord(m.forget());
+        didAddRecords = true;
       }
     }
 
-    if (!m->mAddedAnimations.IsEmpty() ||
-        !m->mChangedAnimations.IsEmpty() ||
-        !m->mRemovedAnimations.IsEmpty()) {
-      ob->AppendMutationRecord(m.forget());
+    if (didAddRecords) {
       ob->ScheduleForRun();
     }
   }
   nsDOMMutationObserver::LeaveMutationHandling();
 }

--- a/dom/base/nsDOMMutationObserver.h
+++ b/dom/base/nsDOMMutationObserver.h
@@ -737,30 +737,31 @@ private:
   nsCOMPtr<nsINode> mNextSibling;
 };
 
 class nsAutoAnimationMutationBatch
 {
   struct Entry;
 
 public:
-  explicit nsAutoAnimationMutationBatch(nsINode* aTarget)
-    : mBatchTarget(nullptr)
+  explicit nsAutoAnimationMutationBatch(nsIDocument* aDocument)
   {
-    Init(aTarget);
+    Init(aDocument);
   }
 
-  void Init(nsINode* aTarget)
+  void Init(nsIDocument* aDocument)
   {
-    if (aTarget && aTarget->OwnerDoc()->MayHaveDOMMutationObservers()) {
-      mBatchTarget = aTarget;
-      mPreviousBatch = sCurrentBatch;
-      sCurrentBatch = this;
-      nsDOMMutationObserver::EnterMutationHandling();
+    if (!aDocument ||
+        !aDocument->MayHaveDOMMutationObservers() ||
+        sCurrentBatch) {
+      return;
     }
+
+    sCurrentBatch = this;
+    nsDOMMutationObserver::EnterMutationHandling();
   }
 
   ~nsAutoAnimationMutationBatch()
   {
     Done();
   }
 
   void Done();
@@ -778,118 +779,130 @@ public:
   static void AddObserver(nsDOMMutationObserver* aObserver)
   {
     if (sCurrentBatch->mObservers.Contains(aObserver)) {
       return;
     }
     sCurrentBatch->mObservers.AppendElement(aObserver);
   }
 
-  static nsINode* GetBatchTarget()
-  {
-    return sCurrentBatch->mBatchTarget;
-  }
-
-  static void AnimationAdded(mozilla::dom::Animation* aAnimation)
+  static void AnimationAdded(mozilla::dom::Animation* aAnimation,
+                             nsINode* aTarget)
   {
     if (!IsBatching()) {
       return;
     }
 
-    Entry* entry = sCurrentBatch->FindEntry(aAnimation);
+    Entry* entry = sCurrentBatch->FindEntry(aAnimation, aTarget);
     if (entry) {
       switch (entry->mState) {
         case eState_RemainedAbsent:
           entry->mState = eState_Added;
           break;
         case eState_Removed:
           entry->mState = eState_RemainedPresent;
           break;
         default:
           NS_NOTREACHED("shouldn't have observed an animation being added "
                         "twice");
       }
     } else {
-      entry = sCurrentBatch->mEntries.AppendElement();
-      entry->mAnimation = aAnimation;
+      entry = sCurrentBatch->AddEntry(aAnimation, aTarget);
       entry->mState = eState_Added;
       entry->mChanged = false;
     }
   }
 
-  static void AnimationChanged(mozilla::dom::Animation* aAnimation)
+  static void AnimationChanged(mozilla::dom::Animation* aAnimation,
+                               nsINode* aTarget)
   {
-    Entry* entry = sCurrentBatch->FindEntry(aAnimation);
+    Entry* entry = sCurrentBatch->FindEntry(aAnimation, aTarget);
     if (entry) {
       NS_ASSERTION(entry->mState == eState_RemainedPresent ||
                    entry->mState == eState_Added,
                    "shouldn't have observed an animation being changed after "
                    "being removed");
       entry->mChanged = true;
     } else {
-      entry = sCurrentBatch->mEntries.AppendElement();
-      entry->mAnimation = aAnimation;
+      entry = sCurrentBatch->AddEntry(aAnimation, aTarget);
       entry->mState = eState_RemainedPresent;
       entry->mChanged = true;
     }
   }
 
-  static void AnimationRemoved(mozilla::dom::Animation* aAnimation)
+  static void AnimationRemoved(mozilla::dom::Animation* aAnimation,
+                               nsINode* aTarget)
   {
-    Entry* entry = sCurrentBatch->FindEntry(aAnimation);
+    Entry* entry = sCurrentBatch->FindEntry(aAnimation, aTarget);
     if (entry) {
       switch (entry->mState) {
         case eState_RemainedPresent:
           entry->mState = eState_Removed;
           break;
         case eState_Added:
           entry->mState = eState_RemainedAbsent;
           break;
         default:
           NS_NOTREACHED("shouldn't have observed an animation being removed "
                         "twice");
       }
     } else {
-      entry = sCurrentBatch->mEntries.AppendElement();
-      entry->mAnimation = aAnimation;
+      entry = sCurrentBatch->AddEntry(aAnimation, aTarget);
       entry->mState = eState_Removed;
       entry->mChanged = false;
     }
   }
 
 private:
-  Entry* FindEntry(mozilla::dom::Animation* aAnimation)
+  Entry* FindEntry(mozilla::dom::Animation* aAnimation, nsINode* aTarget)
   {
-    for (Entry& e : mEntries) {
+    EntryArray* entries = mEntryTable.Get(aTarget);
+    if (!entries) {
+      return nullptr;
+    }
+
+    for (Entry& e : *entries) {
       if (e.mAnimation == aAnimation) {
         return &e;
       }
     }
     return nullptr;
   }
 
+  Entry* AddEntry(mozilla::dom::Animation* aAnimation, nsINode* aTarget)
+  {
+    EntryArray* entries = sCurrentBatch->mEntryTable.LookupOrAdd(aTarget);
+    if (entries->IsEmpty()) {
+      sCurrentBatch->mBatchTargets.AppendElement(aTarget);
+    }
+    Entry* entry = entries->AppendElement();
+    entry->mAnimation = aAnimation;
+    return entry;
+  }
+
   enum State {
     eState_RemainedPresent,
     eState_RemainedAbsent,
     eState_Added,
     eState_Removed
   };
 
   struct Entry
   {
     nsRefPtr<mozilla::dom::Animation> mAnimation;
     State mState;
     bool mChanged;
   };
 
   static nsAutoAnimationMutationBatch* sCurrentBatch;
-  nsAutoAnimationMutationBatch* mPreviousBatch;
   nsAutoTArray<nsDOMMutationObserver*, 2> mObservers;
-  nsTArray<Entry> mEntries;
-  nsINode* mBatchTarget;
+  typedef nsTArray<Entry> EntryArray;
+  nsClassHashtable<nsPtrHashKey<nsINode>, EntryArray> mEntryTable;
+  // List of nodes referred to by mEntryTable so we can sort them
+  nsTArray<nsINode*> mBatchTargets;
 };
 
 inline
 nsDOMMutationObserver*
 nsMutationReceiverBase::Observer()
 {
   return mParent ?
     mParent->Observer() : static_cast<nsDOMMutationObserver*>(mObserver);

--- a/dom/battery/moz.build
+++ b/dom/battery/moz.build
@@ -8,15 +8,13 @@ EXPORTS.mozilla.dom.battery += [
     'Constants.h',
     'Types.h',
 ]
 
 SOURCES += [
     'BatteryManager.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 MOCHITEST_MANIFESTS += ['test/mochitest.ini']

--- a/dom/bindings/moz.build
+++ b/dom/bindings/moz.build
@@ -34,18 +34,16 @@ EXPORTS.mozilla.dom += [
     'PrimitiveConversions.h',
     'RootedDictionary.h',
     'StructuredClone.h',
     'ToJSValue.h',
     'TypedArray.h',
     'UnionMember.h',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/battery',
     '/dom/bluetooth/common/webapi',
     '/dom/camera',
     '/dom/canvas',
     '/dom/geolocation',
     '/dom/html',

--- a/dom/bluetooth/moz.build
+++ b/dom/bluetooth/moz.build
@@ -149,17 +149,15 @@ EXPORTS.mozilla.dom.bluetooth += [
     'common/webapi/BluetoothPbapRequestHandle.h'
 ]
 IPDL_SOURCES += [
     'ipc/BluetoothTypes.ipdlh',
     'ipc/PBluetooth.ipdl',
     'ipc/PBluetoothRequest.ipdl'
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '../base',
     '../network',
     '../system/gonk'
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')

--- a/dom/broadcastchannel/moz.build
+++ b/dom/broadcastchannel/moz.build
@@ -24,9 +24,8 @@ LOCAL_INCLUDES += [
 ]
 
 MOCHITEST_MANIFESTS += ['tests/mochitest.ini']
 MOCHITEST_CHROME_MANIFESTS += ['tests/chrome.ini']
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
-FAIL_ON_WARNINGS = True

--- a/dom/browser-element/BrowserElementChildPreload.js
+++ b/dom/browser-element/BrowserElementChildPreload.js
@@ -564,43 +564,52 @@ BrowserElementChild.prototype = {
     let win = e.target.ownerDocument.defaultView;
     // Ignore metas which don't come from the top-level
     // <iframe mozbrowser> window.
     if (win != content) {
       debug('Not top level!');
       return;
     }
 
-    if (!e.target.name) {
+    var name = e.target.name;
+    var property = e.target.getAttributeNS(null, "property");
+
+    if (!name && !property) {
       return;
     }
 
-    debug('Got metaChanged: (' + e.target.name + ') ' + e.target.content);
+    debug('Got metaChanged: (' + (name || property) + ') ' +
+          e.target.content);
 
     let handlers = {
-      'viewmode': this._genericMetaHandler.bind(null, 'viewmode'),
-      'theme-color': this._genericMetaHandler.bind(null, 'theme-color'),
-      'theme-group': this._genericMetaHandler.bind(null, 'theme-group'),
+      'viewmode': this._genericMetaHandler,
+      'theme-color': this._genericMetaHandler,
+      'theme-group': this._genericMetaHandler,
       'application-name': this._applicationNameChangedHandler
     };
+    let handler = handlers[name];
 
-    let handler = handlers[e.target.name];
+    if ((property || name).match(/^og:/)) {
+      name = property || name;
+      handler = this._genericMetaHandler;
+    }
+
     if (handler) {
-      handler(e.type, e.target);
+      handler(name, e.type, e.target);
     }
   },
 
-  _applicationNameChangedHandler: function(eventType, target) {
+  _applicationNameChangedHandler: function(name, eventType, target) {
     if (eventType !== 'DOMMetaAdded') {
       // Bug 1037448 - Decide what to do when <meta name="application-name">
       // changes
       return;
     }
 
-    let meta = { name: 'application-name',
+    let meta = { name: name,
                  content: target.content };
 
     let lang;
     let elm;
 
     for (elm = target;
          !lang && elm && elm.nodeType == target.ELEMENT_NODE;
          elm = elm.parentNode) {

--- a/dom/browser-element/mochitest/browserElement_Metachange.js
+++ b/dom/browser-element/mochitest/browserElement_Metachange.js
@@ -19,16 +19,20 @@ function createHtmlWithLang(meta, lang) 
 function createMeta(name, content) {
   return '<meta name="' + name + '" content="' + content + '">';
 }
 
 function createMetaWithLang(name, content, lang) {
   return '<meta name="' + name + '" content="' + content + '" lang="' + lang + '">';
 }
 
+function createMetaWithProperty(property, content) {
+  return '<meta property="' + property + '" content="' + content + '">';
+}
+
 function runTest() {
   var iframe1 = document.createElement('iframe');
   iframe1.setAttribute('mozbrowser', 'true');
   document.body.appendChild(iframe1);
 
   // iframe2 is a red herring; we modify its meta elements but don't listen for
   // metachanges; we want to make sure that its metachange events aren't
   // picked up by the listener on iframe1.
@@ -126,16 +130,36 @@ function runTest() {
       // Test the content-language
       iframe1.src = "http://test/tests/dom/browser-element/mochitest/file_browserElement_Metachange.sjs?ru|dk";
     }
     else if (numMetaChanges == 10) {
       is(e.detail.name, 'application-name', 'name matches');
       is(e.detail.content, 'sjs', 'content matches');
       is(e.detail.lang, 'dk', 'language matches');
 
+      // Test Open Graph property
+      iframe1.src = createHtml(createMetaWithProperty('og:description', 'Fascinating article'));
+
+      // We should not get event if property doesn't start with 'og:'
+      iframe3.src = createHtml(createMetaWithProperty('go:description', 'Fascinating article'));
+    }
+    else if (numMetaChanges == 11) {
+      is(e.detail.name, 'og:description', 'property name matches');
+      is(e.detail.content, 'Fascinating article', 'content matches');
+
+      // Sometimes 'name' is used instead of 'property'. Verify that works.
+      iframe1.src = createHtml(createMeta('og:title', 'One weird trick!'));
+
+      // We should not get event if property doesn't start with 'og:'
+      iframe3.src = createHtml(createMeta('go:title', 'One weird trick!'));
+    }
+    else if (numMetaChanges == 12) {
+      is(e.detail.name, 'og:title', 'property name matches');
+      is(e.detail.content, 'One weird trick!', 'content matches');
+
       // Test the language
       SimpleTest.finish();
     } else {
       ok(false, 'Too many metachange events.');
     }
   });
 
   iframe3.addEventListener('mozbrowsermetachange', function(e) {

--- a/dom/browser-element/moz.build
+++ b/dom/browser-element/moz.build
@@ -27,18 +27,16 @@ EXTRA_COMPONENTS += [
     'BrowserElementParent.js',
     'BrowserElementParent.manifest',
 ]
 
 EXTRA_JS_MODULES += [
     'BrowserElementPromptService.jsm',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '../bluetooth',
     '/dom/html',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

--- a/dom/cache/moz.build
+++ b/dom/cache/moz.build
@@ -82,18 +82,16 @@ IPDL_SOURCES += [
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '../workers',
 ]
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'
 
 MOCHITEST_MANIFESTS += [
     'test/mochitest/mochitest.ini',
 ]
 
 MOCHITEST_CHROME_MANIFESTS += [
     'test/mochitest/chrome.ini',

--- a/dom/camera/CameraPreviewMediaStream.cpp
+++ b/dom/camera/CameraPreviewMediaStream.cpp
@@ -31,17 +31,19 @@ FakeMediaStreamGraph::DispatchToMainThre
 CameraPreviewMediaStream::CameraPreviewMediaStream(DOMMediaStream* aWrapper)
   : MediaStream(aWrapper)
   , mMutex("mozilla::camera::CameraPreviewMediaStream")
   , mInvalidatePending(0)
   , mDiscardedFrames(0)
   , mRateLimit(false)
   , mTrackCreated(false)
 {
-  SetGraphImpl(MediaStreamGraph::GetInstance());
+  SetGraphImpl(
+      MediaStreamGraph::GetInstance(
+        MediaStreamGraph::SYSTEM_THREAD_DRIVER, AudioChannel::Normal));
   mFakeMediaStreamGraph = new FakeMediaStreamGraph();
   mIsConsumed = false;
 }
 
 void
 CameraPreviewMediaStream::AddAudioOutput(void* aKey)
 {
 }

--- a/dom/camera/moz.build
+++ b/dom/camera/moz.build
@@ -56,18 +56,16 @@ if CONFIG['MOZ_B2G_CAMERA']:
         'CameraTestHardware.manifest',
     ]
 else:
     UNIFIED_SOURCES += [
         'FallbackCameraControl.cpp',
         'FallbackCameraManager.cpp',
     ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '../base',
     '/media/libyuv/include',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 # Suppress some GCC warnings being treated as errors:

--- a/dom/canvas/compiledtest/moz.build
+++ b/dom/canvas/compiledtest/moz.build
@@ -6,13 +6,11 @@
 
 GeckoCppUnitTests([
     'TestWebGLElementArrayCache',
 ])
 
 if CONFIG['GNU_CXX']:
     CXXFLAGS += ['-Wshadow']
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '../',
 ]

--- a/dom/canvas/moz.build
+++ b/dom/canvas/moz.build
@@ -138,18 +138,16 @@ UNIFIED_SOURCES += [
     'WebGLVertexArrayObject.cpp',
 ]
 
 LOCAL_INCLUDES += [
     '../..', # Support `#include "mfbt/RefPtr.h"`
     '/js/xpconnect/wrappers',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '../workers',
     '/dom/base',
     '/dom/html',
     '/dom/svg',

--- a/dom/cellbroadcast/moz.build
+++ b/dom/cellbroadcast/moz.build
@@ -30,11 +30,9 @@ EXPORTS.mozilla.dom.cellbroadcast += [
 ]
 
 IPDL_SOURCES += [
     'ipc/PCellBroadcast.ipdl',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'

--- a/dom/crypto/moz.build
+++ b/dom/crypto/moz.build
@@ -14,18 +14,16 @@ EXPORTS.mozilla.dom += [
 
 UNIFIED_SOURCES += [
     'CryptoBuffer.cpp',
     'CryptoKey.cpp',
     'KeyAlgorithmProxy.cpp',
     'WebCryptoTask.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/security/manager/ssl',
 ]
 

--- a/dom/datastore/moz.build
+++ b/dom/datastore/moz.build
@@ -40,9 +40,8 @@ EXTRA_JS_MODULES += [
     'DataStoreDB.jsm',
 ]
 
 MOCHITEST_MANIFESTS += ['tests/mochitest.ini']
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
-FAIL_ON_WARNINGS = True

--- a/dom/devicestorage/moz.build
+++ b/dom/devicestorage/moz.build
@@ -27,18 +27,16 @@ UNIFIED_SOURCES += [
     'DeviceStorageStatics.cpp',
     'nsDeviceStorage.cpp',
 ]
 
 IPDL_SOURCES += [
     'PDeviceStorageRequest.ipdl',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/ipc',
 ]
 

--- a/dom/encoding/moz.build
+++ b/dom/encoding/moz.build
@@ -13,18 +13,16 @@ EXPORTS.mozilla.dom += [
 
 UNIFIED_SOURCES += [
     'EncodingUtils.cpp',
     'FallbackEncoding.cpp',
     'TextDecoder.cpp',
     'TextEncoder.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/intl/locale',
 ]
 
 props2arrays = '/intl/locale/props2arrays.py'
 prefixes = (
     'domainsfallbacks',

--- a/dom/events/moz.build
+++ b/dom/events/moz.build
@@ -119,18 +119,16 @@ UNIFIED_SOURCES += [
 SOURCES += [
     'CustomEvent.cpp',
     'EventStateManager.cpp',
 ]
 
 if CONFIG['MOZ_WEBSPEECH']:
     UNIFIED_SOURCES += ['SpeechRecognitionError.cpp']
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/docshell/base',
     '/dom/base',
     '/dom/html',
     '/dom/settings',

--- a/dom/fetch/moz.build
+++ b/dom/fetch/moz.build
@@ -39,12 +39,11 @@ LOCAL_INCLUDES += [
     # For HttpBaseChannel.h dependencies
     '/netwerk/base',
     # For nsDataHandler.h
     '/netwerk/protocol/data',
     # For HttpBaseChannel.h
     '/netwerk/protocol/http',
 ]
 
-FAIL_ON_WARNINGS = True
 FINAL_LIBRARY = 'xul'
 
 include('/ipc/chromium/chromium-config.mozbuild')

--- a/dom/filehandle/moz.build
+++ b/dom/filehandle/moz.build
@@ -21,18 +21,16 @@ UNIFIED_SOURCES += [
     'FileRequest.cpp',
     'FileService.cpp',
     'FileStreamWrappers.cpp',
     'MemoryStreams.cpp',
     'MetadataHelper.cpp',
     'MutableFile.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '../base',
 ]
 
 FINAL_LIBRARY = 'xul'
 

--- a/dom/filesystem/moz.build
+++ b/dom/filesystem/moz.build
@@ -37,10 +37,10 @@ IPDL_SOURCES += [
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
-if not CONFIG['CLANG_CXX']:
-    FAIL_ON_WARNINGS = True
+if CONFIG['CLANG_CXX']:
+    ALLOW_COMPILER_WARNINGS = True

--- a/dom/fmradio/ipc/moz.build
+++ b/dom/fmradio/ipc/moz.build
@@ -13,18 +13,16 @@ EXPORTS.mozilla.dom += [
 
 UNIFIED_SOURCES += [
     'FMRadioChild.cpp',
     'FMRadioParent.cpp',
     'FMRadioRequestChild.cpp',
     'FMRadioRequestParent.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 

--- a/dom/fmradio/moz.build
+++ b/dom/fmradio/moz.build
@@ -22,15 +22,13 @@ if CONFIG['MOZ_B2G_FM']:
 
     FINAL_LIBRARY = 'xul'
 
 IPDL_SOURCES += [
     'ipc/PFMRadio.ipdl',
     'ipc/PFMRadioRequest.ipdl',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '../base',
     '../system/gonk',
 ]
 include('/ipc/chromium/chromium-config.mozbuild')

--- a/dom/gamepad/moz.build
+++ b/dom/gamepad/moz.build
@@ -38,18 +38,16 @@ elif CONFIG['MOZ_GAMEPAD_BACKEND'] == 'l
     UNIFIED_SOURCES += [
         'linux/LinuxGamepad.cpp'
     ]
 elif CONFIG['MOZ_GAMEPAD_BACKEND'] == 'android':
     UNIFIED_SOURCES += [
         'android/AndroidGamepad.cpp'
     ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
 CFLAGS += CONFIG['GLIB_CFLAGS']

--- a/dom/geolocation/moz.build
+++ b/dom/geolocation/moz.build
@@ -16,18 +16,16 @@ SOURCES += [
 
 UNIFIED_SOURCES += [
     'MLSFallback.cpp',
     'nsGeoGridFuzzer.cpp',
     'nsGeolocationSettings.cpp',
     'nsGeoPosition.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/ipc',
 ]
 

--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -1825,16 +1825,24 @@ HTMLMediaElement::CaptureStreamInternal(
   if (!window) {
     return nullptr;
   }
 #ifdef MOZ_EME
   if (ContainsRestrictedContent()) {
     return nullptr;
   }
 #endif
+
+  if (!aGraph) {
+    MediaStreamGraph::GraphDriverType graphDriverType =
+      HasAudio() ? MediaStreamGraph::AUDIO_THREAD_DRIVER
+                 : MediaStreamGraph::SYSTEM_THREAD_DRIVER;
+    aGraph = MediaStreamGraph::GetInstance(graphDriverType, mAudioChannel);
+  }
+
   OutputMediaStream* out = mOutputStreams.AppendElement();
   out->mStream = DOMMediaStream::CreateTrackUnionStream(window, aGraph);
   nsRefPtr<nsIPrincipal> principal = GetCurrentPrincipal();
   out->mStream->CombineWithPrincipal(principal);
   out->mStream->SetCORSMode(mCORSMode);
   out->mFinishWhenEnded = aFinishWhenEnded;
 
   mAudioCaptured = true;
@@ -3046,17 +3054,18 @@ void HTMLMediaElement::SetupSrcMediaStre
   }
 
   // XXX Remove this if with CameraPreviewMediaStream per bug 1124630.
   if (!mSrcStream->GetStream()->AsCameraPreviewStream()) {
     // Now that we have access to |mSrcStream| we can pipe it to our shadow
     // version |mPlaybackStream|. If two media elements are playing the
     // same realtime DOMMediaStream, this allows them to pause playback
     // independently of each other.
-    mPlaybackStream = DOMMediaStream::CreateTrackUnionStream(window);
+    MediaStreamGraph* graph = mSrcStream->GetStream()->Graph();
+    mPlaybackStream = DOMMediaStream::CreateTrackUnionStream(window, graph);
     mPlaybackStreamInputPort = mPlaybackStream->GetStream()->AsProcessedStream()->
       AllocateInputPort(mSrcStream->GetStream(), MediaInputPort::FLAG_BLOCK_OUTPUT);
 
     nsRefPtr<nsIPrincipal> principal = GetCurrentPrincipal();
     mPlaybackStream->CombineWithPrincipal(principal);
 
     // Let |mSrcStream| decide when the stream has finished.
     GetSrcMediaStream()->AsProcessedStream()->SetAutofinish(true);
@@ -4704,17 +4713,19 @@ NS_IMETHODIMP HTMLMediaElement::WindowAu
   bool captured = OwnerDoc()->GetInnerWindow()->GetAudioCaptured();
 
   if (captured != mAudioCapturedByWindow) {
     if (captured) {
       mAudioCapturedByWindow = true;
       nsCOMPtr<nsPIDOMWindow> window =
         do_QueryInterface(OwnerDoc()->GetParentObject());
       uint64_t id = window->WindowID();
-      MediaStreamGraph* msg = MediaStreamGraph::GetInstance();
+      MediaStreamGraph* msg =
+        MediaStreamGraph::GetInstance(MediaStreamGraph::AUDIO_THREAD_DRIVER,
+                                      AudioChannel::Normal);
 
       if (!mPlaybackStream) {
         nsRefPtr<DOMMediaStream> stream = CaptureStreamInternal(false, msg);
         mCaptureStreamPort = msg->ConnectToCaptureStream(id, stream->GetStream());
       } else {
         mCaptureStreamPort = msg->ConnectToCaptureStream(id, mPlaybackStream->GetStream());
       }
     } else {

--- a/dom/html/moz.build
+++ b/dom/html/moz.build
@@ -217,18 +217,16 @@ SOURCES += [
     'PluginDocument.cpp',
 ]
 
 EXTRA_COMPONENTS += [
     'htmlMenuBuilder.js',
     'htmlMenuBuilder.manifest'
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '/caps',
     '/docshell/base',
     '/dom/base',
     '/dom/canvas',
     '/dom/media/',

--- a/dom/icc/moz.build
+++ b/dom/icc/moz.build
@@ -43,17 +43,15 @@ IPDL_SOURCES += [
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk' and CONFIG['MOZ_B2G_RIL']:
     EXTRA_COMPONENTS += [
         'gonk/IccService.js',
         'gonk/IccService.manifest',
         'gonk/StkCmdFactory.js',
         'gonk/StkCmdFactory.manifest'
     ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/dom/system/gonk',
 ]

--- a/dom/indexedDB/moz.build
+++ b/dom/indexedDB/moz.build
@@ -82,18 +82,16 @@ IPDL_SOURCES += [
     'PBackgroundIDBVersionChangeTransaction.ipdl',
     'PIndexedDBPermissionRequest.ipdl',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '/db/sqlite3/src',
     '/dom/base',
     '/dom/storage',
     '/dom/workers',
     '/ipc/glue',
     '/xpcom/build',
     '/xpcom/threads',

--- a/dom/inputport/InputPort.cpp
+++ b/dom/inputport/InputPort.cpp
@@ -1,14 +1,15 @@
 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "MediaStreamGraph.h"
 #include "DOMMediaStream.h"
 #include "InputPortData.h"
 #include "InputPortListeners.h"
 #include "mozilla/AsyncEventDispatcher.h"
 #include "mozilla/dom/InputPort.h"
 
 namespace mozilla {
 namespace dom {
@@ -55,17 +56,20 @@ InputPort::Init(nsIInputPortData* aData,
     return;
   }
 
   aData->GetConnected(&mIsConnected);
 
   mInputPortListener = static_cast<InputPortListener*>(aListener);
   mInputPortListener->RegisterInputPort(this);
 
-  mStream = DOMMediaStream::CreateSourceStream(GetOwner());
+  MediaStreamGraph* graph =
+    MediaStreamGraph::GetInstance(MediaStreamGraph::SYSTEM_THREAD_DRIVER,
+                                  AudioChannel::Normal);
+  mStream = DOMMediaStream::CreateSourceStream(GetOwner(), graph);
 }
 
 void
 InputPort::Shutdown()
 {
   MOZ_ASSERT(mInputPortListener);
   if (mInputPortListener) {
     mInputPortListener->UnregisterInputPort(this);

--- a/dom/inputport/moz.build
+++ b/dom/inputport/moz.build
@@ -39,10 +39,8 @@ XPIDL_MODULE = 'dom_inputport'
 
 MOCHITEST_MANIFESTS += ['test/mochitest/mochitest.ini']
 
 XPCSHELL_TESTS_MANIFESTS += ['test/xpcshell/xpcshell.ini']
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True
\ No newline at end of file

--- a/dom/ipc/moz.build
+++ b/dom/ipc/moz.build
@@ -107,18 +107,16 @@ IPDL_SOURCES += [
     'PMemoryReportRequest.ipdl',
     'PNuwa.ipdl',
     'PPluginWidget.ipdl',
     'PProcessHangMonitor.ipdl',
     'PScreenManager.ipdl',
     'PTabContext.ipdlh',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['MOZ_SANDBOX'] and CONFIG['OS_TARGET'] == 'Darwin':
     USE_LIBS += [
         'mozsandbox',
     ]

--- a/dom/json/moz.build
+++ b/dom/json/moz.build
@@ -7,18 +7,16 @@
 EXPORTS += [
     'nsJSON.h',
 ]
 
 UNIFIED_SOURCES += [
     'nsJSON.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
 FINAL_LIBRARY = 'xul'
 
 XPCSHELL_TESTS_MANIFESTS += ['test/unit/xpcshell.ini']
 MOCHITEST_MANIFESTS += ['test/mochitest.ini']

--- a/dom/jsurl/moz.build
+++ b/dom/jsurl/moz.build
@@ -7,18 +7,16 @@
 EXPORTS += [
     'nsJSProtocolHandler.h',
 ]
 
 UNIFIED_SOURCES += [
     'nsJSProtocolHandler.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     "/dom/base",
     "/netwerk/base",
 ]
 
 FINAL_LIBRARY = 'xul'
 
 include('/ipc/chromium/chromium-config.mozbuild')

--- a/dom/mathml/moz.build
+++ b/dom/mathml/moz.build
@@ -4,17 +4,15 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 UNIFIED_SOURCES += [
     'nsMathMLElement.cpp',
     'nsMathMLElementFactory.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 

--- a/dom/media/CanvasCaptureMediaStream.cpp
+++ b/dom/media/CanvasCaptureMediaStream.cpp
@@ -351,15 +351,18 @@ CanvasCaptureMediaStream::Init(const dom
   return mOutputStreamDriver->Start();
 }
 
 already_AddRefed<CanvasCaptureMediaStream>
 CanvasCaptureMediaStream::CreateSourceStream(nsIDOMWindow* aWindow,
                                              HTMLCanvasElement* aCanvas)
 {
   nsRefPtr<CanvasCaptureMediaStream> stream = new CanvasCaptureMediaStream(aCanvas);
-  stream->InitSourceStream(aWindow);
+  MediaStreamGraph* graph =
+    MediaStreamGraph::GetInstance(MediaStreamGraph::SYSTEM_THREAD_DRIVER,
+                                  AudioChannel::Normal);
+  stream->InitSourceStream(aWindow, graph);
   return stream.forget();
 }
 
 } // namespace dom
 } // namespace mozilla
 

--- a/dom/media/DOMMediaStream.cpp
+++ b/dom/media/DOMMediaStream.cpp
@@ -5,16 +5,17 @@
 
 #include "DOMMediaStream.h"
 #include "nsContentUtils.h"
 #include "nsServiceManagerUtils.h"
 #include "nsIUUIDGenerator.h"
 #include "mozilla/dom/MediaStreamBinding.h"
 #include "mozilla/dom/LocalMediaStreamBinding.h"
 #include "mozilla/dom/AudioNode.h"
+#include "AudioChannelAgent.h"
 #include "mozilla/dom/AudioTrack.h"
 #include "mozilla/dom/AudioTrackList.h"
 #include "mozilla/dom/VideoTrack.h"
 #include "mozilla/dom/VideoTrackList.h"
 #include "mozilla/dom/HTMLCanvasElement.h"
 #include "MediaStreamGraph.h"
 #include "AudioStreamTrack.h"
 #include "VideoStreamTrack.h"
@@ -278,43 +279,34 @@ DOMMediaStream::IsFinished()
   return !mStream || mStream->IsFinished();
 }
 
 void
 DOMMediaStream::InitSourceStream(nsIDOMWindow* aWindow,
                                  MediaStreamGraph* aGraph)
 {
   mWindow = aWindow;
-  if (!aGraph) {
-    aGraph = MediaStreamGraph::GetInstance();
-  }
   InitStreamCommon(aGraph->CreateSourceStream(this));
 }
 
 void
 DOMMediaStream::InitTrackUnionStream(nsIDOMWindow* aWindow,
                                      MediaStreamGraph* aGraph)
 {
   mWindow = aWindow;
 
-  if (!aGraph) {
-    aGraph = MediaStreamGraph::GetInstance();
-  }
   InitStreamCommon(aGraph->CreateTrackUnionStream(this));
 }
 
 void
 DOMMediaStream::InitAudioCaptureStream(nsIDOMWindow* aWindow,
                                        MediaStreamGraph* aGraph)
 {
   mWindow = aWindow;
 
-  if (!aGraph) {
-    aGraph = MediaStreamGraph::GetInstance();
-  }
   InitStreamCommon(aGraph->CreateAudioCaptureStream(this));
 }
 
 void
 DOMMediaStream::InitStreamCommon(MediaStream* aStream)
 {
   mStream = aStream;
 
@@ -717,17 +709,21 @@ DOMHwMediaStream::DOMHwMediaStream()
 DOMHwMediaStream::~DOMHwMediaStream()
 {
 }
 
 already_AddRefed<DOMHwMediaStream>
 DOMHwMediaStream::CreateHwStream(nsIDOMWindow* aWindow)
 {
   nsRefPtr<DOMHwMediaStream> stream = new DOMHwMediaStream();
-  stream->InitSourceStream(aWindow);
+
+  MediaStreamGraph* graph =
+    MediaStreamGraph::GetInstance(MediaStreamGraph::SYSTEM_THREAD_DRIVER,
+                                  AudioChannel::Normal);
+  stream->InitSourceStream(aWindow, graph);
   stream->Init(stream->GetStream());
 
   return stream.forget();
 }
 
 void
 DOMHwMediaStream::Init(MediaStream* stream)
 {

--- a/dom/media/DOMMediaStream.h
+++ b/dom/media/DOMMediaStream.h
@@ -185,30 +185,30 @@ public:
   // Webrtc allows the remote side to name a stream whatever it wants, and we
   // need to surface this to content.
   void AssignId(const nsAString& aID) { mID = aID; }
 
   /**
    * Create an nsDOMMediaStream whose underlying stream is a SourceMediaStream.
    */
   static already_AddRefed<DOMMediaStream> CreateSourceStream(nsIDOMWindow* aWindow,
-                                                             MediaStreamGraph* aGraph = nullptr);
+                                                             MediaStreamGraph* aGraph);
 
   /**
    * Create an nsDOMMediaStream whose underlying stream is a TrackUnionStream.
    */
   static already_AddRefed<DOMMediaStream> CreateTrackUnionStream(nsIDOMWindow* aWindow,
-                                                                 MediaStreamGraph* aGraph = nullptr);
+                                                                 MediaStreamGraph* aGraph);
 
   /**
    * Create an nsDOMMediaStream whose underlying stream is an
    * AudioCaptureStream
    */
   static already_AddRefed<DOMMediaStream> CreateAudioCaptureStream(
-    nsIDOMWindow* aWindow, MediaStreamGraph* aGraph = nullptr);
+    nsIDOMWindow* aWindow, MediaStreamGraph* aGraph);
 
   void SetLogicalStreamStartTime(StreamTime aTime)
   {
     mLogicalStreamStartTime = aTime;
   }
 
   // Notifications from StreamListener.
   // BindDOMTrack should only be called when it's safe to run script.
@@ -260,21 +260,21 @@ public:
 
   virtual void NotifyMediaStreamTrackEnded(MediaStreamTrack* aTrack);
 
 protected:
   virtual ~DOMMediaStream();
 
   void Destroy();
   void InitSourceStream(nsIDOMWindow* aWindow,
-                        MediaStreamGraph* aGraph = nullptr);
+                        MediaStreamGraph* aGraph);
   void InitTrackUnionStream(nsIDOMWindow* aWindow,
-                            MediaStreamGraph* aGraph = nullptr);
+                            MediaStreamGraph* aGraph);
   void InitAudioCaptureStream(nsIDOMWindow* aWindow,
-                              MediaStreamGraph* aGraph = nullptr);
+                              MediaStreamGraph* aGraph);
   void InitStreamCommon(MediaStream* aStream);
   already_AddRefed<AudioTrack> CreateAudioTrack(AudioStreamTrack* aStreamTrack);
   already_AddRefed<VideoTrack> CreateVideoTrack(VideoStreamTrack* aStreamTrack);
 
   // Called when MediaStreamGraph has finished an iteration where tracks were
   // created.
   void TracksCreated();
 
@@ -346,30 +346,30 @@ public:
 
   virtual MediaEngineSource* GetMediaEngine(TrackID aTrackID) { return nullptr; }
 
   /**
    * Create an nsDOMLocalMediaStream whose underlying stream is a SourceMediaStream.
    */
   static already_AddRefed<DOMLocalMediaStream>
   CreateSourceStream(nsIDOMWindow* aWindow,
-                     MediaStreamGraph* aGraph = nullptr);
+                     MediaStreamGraph* aGraph);
 
   /**
    * Create an nsDOMLocalMediaStream whose underlying stream is a TrackUnionStream.
    */
   static already_AddRefed<DOMLocalMediaStream>
   CreateTrackUnionStream(nsIDOMWindow* aWindow,
-                         MediaStreamGraph* aGraph = nullptr);
+                         MediaStreamGraph* aGraph);
 
   /**
    * Create an nsDOMLocalMediaStream whose underlying stream is an
    * AudioCaptureStream. */
   static already_AddRefed<DOMLocalMediaStream> CreateAudioCaptureStream(
-    nsIDOMWindow* aWindow, MediaStreamGraph* aGraph = nullptr);
+    nsIDOMWindow* aWindow, MediaStreamGraph* aGraph);
 
 protected:
   virtual ~DOMLocalMediaStream();
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(DOMLocalMediaStream,
                               NS_DOMLOCALMEDIASTREAM_IID)
 
@@ -383,17 +383,17 @@ public:
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DOMAudioNodeMediaStream, DOMMediaStream)
 
   /**
    * Create a DOMAudioNodeMediaStream whose underlying stream is a TrackUnionStream.
    */
   static already_AddRefed<DOMAudioNodeMediaStream>
   CreateTrackUnionStream(nsIDOMWindow* aWindow,
                          AudioNode* aNode,
-                         MediaStreamGraph* aGraph = nullptr);
+                         MediaStreamGraph* aGraph);
 
 protected:
   ~DOMAudioNodeMediaStream();
 
 private:
   // If this object wraps a stream owned by an AudioNode, we need to ensure that
   // the node isn't cycle-collected too early.
   nsRefPtr<AudioNode> mStreamNode;

--- a/dom/media/MediaManager.cpp
+++ b/dom/media/MediaManager.cpp
@@ -477,22 +477,23 @@ nsresult AudioDevice::Allocate(const dom
  */
 class nsDOMUserMediaStream : public DOMLocalMediaStream
 {
 public:
   static already_AddRefed<nsDOMUserMediaStream>
   CreateTrackUnionStream(nsIDOMWindow* aWindow,
                          GetUserMediaCallbackMediaStreamListener* aListener,
                          MediaEngineSource* aAudioSource,
-                         MediaEngineSource* aVideoSource)
+                         MediaEngineSource* aVideoSource,
+                         MediaStreamGraph* aMSG)
   {
     nsRefPtr<nsDOMUserMediaStream> stream = new nsDOMUserMediaStream(aListener,
                                                                      aAudioSource,
                                                                      aVideoSource);
-    stream->InitTrackUnionStream(aWindow);
+    stream->InitTrackUnionStream(aWindow, aMSG);
     return stream.forget();
   }
 
   nsDOMUserMediaStream(GetUserMediaCallbackMediaStreamListener* aListener,
                        MediaEngineSource *aAudioSource,
                        MediaEngineSource *aVideoSource) :
     mListener(aListener),
     mAudioSource(aAudioSource),
@@ -781,39 +782,46 @@ public:
         branch->GetIntPref("media.getusermedia.agc", &agc);
         branch->GetBoolPref("media.getusermedia.noise_enabled", &noise_on);
         branch->GetIntPref("media.getusermedia.noise", &noise);
         branch->GetIntPref("media.getusermedia.playout_delay", &playout_delay);
       }
     }
 #endif
 
-    MediaStreamGraph* msg = MediaStreamGraph::GetInstance();
+    MediaStreamGraph::GraphDriverType graphDriverType =
+      mAudioSource ? MediaStreamGraph::AUDIO_THREAD_DRIVER
+                   : MediaStreamGraph::SYSTEM_THREAD_DRIVER;
+    MediaStreamGraph* msg =
+      MediaStreamGraph::GetInstance(graphDriverType,
+                                    dom::AudioChannel::Normal);
+
     nsRefPtr<SourceMediaStream> stream = msg->CreateSourceStream(nullptr);
 
     nsRefPtr<DOMLocalMediaStream> domStream;
     // AudioCapture is a special case, here, in the sense that we're not really
     // using the audio source and the SourceMediaStream, which acts as
     // placeholders. We re-route a number of stream internaly in the MSG and mix
     // them down instead.
     if (mAudioSource &&
         mAudioSource->GetMediaSource() == dom::MediaSourceEnum::AudioCapture) {
-      domStream = DOMLocalMediaStream::CreateAudioCaptureStream(window);
+      domStream = DOMLocalMediaStream::CreateAudioCaptureStream(window, msg);
       // It should be possible to pipe the capture stream to anything. CORS is
       // not a problem here, we got explicit user content.
       domStream->SetPrincipal(window->GetExtantDoc()->NodePrincipal());
       msg->RegisterCaptureStreamForWindow(
             mWindowID, domStream->GetStream()->AsProcessedStream());
       window->SetAudioCapture(true);
     } else {
       // Normal case, connect the source stream to the track union stream to
       // avoid us blocking
       nsRefPtr<nsDOMUserMediaStream> trackunion =
         nsDOMUserMediaStream::CreateTrackUnionStream(window, mListener,
-                                                     mAudioSource, mVideoSource);
+                                                     mAudioSource, mVideoSource,
+                                                     msg);
       trackunion->GetStream()->AsProcessedStream()->SetAutofinish(true);
       nsRefPtr<MediaInputPort> port = trackunion->GetStream()->AsProcessedStream()->
         AllocateInputPort(stream, MediaInputPort::FLAG_BLOCK_OUTPUT);
       trackunion->mSourceStream = stream;
       trackunion->mPort = port.forget();
       // Log the relationship between SourceMediaStream and TrackUnion stream
       // Make sure logger starts before capture
       AsyncLatencyLogger::Get(true);
@@ -2826,17 +2834,20 @@ GetUserMediaCallbackMediaStreamListener:
                              this, nullptr, nullptr,
                              nullptr, mVideoSource,
                              mFinished, mWindowID, nullptr));
   } else if (mAudioSource &&
              mAudioSource->GetMediaSource() == dom::MediaSourceEnum::AudioCapture) {
     nsCOMPtr<nsPIDOMWindow> window = nsGlobalWindow::GetInnerWindowWithId(mWindowID);
     MOZ_ASSERT(window);
     window->SetAudioCapture(false);
-    MediaStreamGraph::GetInstance()->UnregisterCaptureStreamForWindow(mWindowID);
+    MediaStreamGraph* graph =
+      MediaStreamGraph::GetInstance(MediaStreamGraph::AUDIO_THREAD_DRIVER,
+                                    dom::AudioChannel::Normal);
+    graph->UnregisterCaptureStreamForWindow(mWindowID);
     mStream->Destroy();
   }
 }
 
 // Stop backend for track
 
 void
 GetUserMediaCallbackMediaStreamListener::StopTrack(TrackID aID, bool aIsAudio)

--- a/dom/media/MediaStreamGraph.cpp
+++ b/dom/media/MediaStreamGraph.cpp
@@ -53,17 +53,17 @@ PRLogModuleInfo* gMediaStreamGraphLog;
 #  else
 #    define LIFECYCLE_LOG(...) printf(__VA_ARGS__);printf("\n");
 #  endif
 #else
 #  define LIFECYCLE_LOG(...)
 #endif
 
 /**
- * The singleton graph instance.
+ * A hash table containing the graph instances, one per AudioChannel.
  */
 static nsDataHashtable<nsUint32HashKey, MediaStreamGraphImpl*> gGraphs;
 
 MediaStreamGraphImpl::~MediaStreamGraphImpl()
 {
   NS_ASSERTION(IsEmpty(),
                "All streams should have been destroyed by messages from the main thread");
   STREAM_LOG(LogLevel::Debug, ("MediaStreamGraph %p destroyed", this));
@@ -2860,34 +2860,33 @@ ProcessedMediaStream::DestroyImpl()
   }
   MediaStream::DestroyImpl();
   // The stream order is only important if there are connections, in which
   // case MediaInputPort::Disconnect() called SetStreamOrderDirty().
   // MediaStreamGraphImpl::RemoveStreamGraphThread() will also call
   // SetStreamOrderDirty(), for other reasons.
 }
 
-MediaStreamGraphImpl::MediaStreamGraphImpl(bool aRealtime,
+MediaStreamGraphImpl::MediaStreamGraphImpl(GraphDriverType aDriverRequested,
                                            TrackRate aSampleRate,
-                                           bool aStartWithAudioDriver,
                                            dom::AudioChannel aChannel)
   : MediaStreamGraph(aSampleRate)
   , mPortCount(0)
   , mNeedAnotherIteration(false)
   , mGraphDriverAsleep(false)
   , mMonitor("MediaStreamGraphImpl")
   , mLifecycleState(LIFECYCLE_THREAD_NOT_STARTED)
   , mEndTime(GRAPH_TIME_MAX)
   , mForceShutDown(false)
   , mPostedRunInStableStateEvent(false)
   , mFlushSourcesNow(false)
   , mFlushSourcesOnNextIteration(false)
   , mDetectedNotRunning(false)
   , mPostedRunInStableState(false)
-  , mRealtime(aRealtime)
+  , mRealtime(aDriverRequested != OFFLINE_THREAD_DRIVER)
   , mNonRealtimeProcessing(false)
   , mStreamOrderDirty(false)
   , mLatencyLog(AsyncLatencyLogger::Get())
 #ifdef MOZ_WEBRTC
   , mFarendObserverRef(nullptr)
 #endif
   , mMemoryReportMonitor("MSGIMemory")
   , mSelfRef(this)
@@ -2898,17 +2897,17 @@ MediaStreamGraphImpl::MediaStreamGraphIm
 #endif
   , mAudioChannel(static_cast<uint32_t>(aChannel))
 {
   if (!gMediaStreamGraphLog) {
     gMediaStreamGraphLog = PR_NewLogModule("MediaStreamGraph");
   }
 
   if (mRealtime) {
-    if (aStartWithAudioDriver) {
+    if (aDriverRequested == AUDIO_THREAD_DRIVER) {
       AudioCallbackDriver* driver = new AudioCallbackDriver(this, aChannel);
       mDriver = driver;
       mMixer.AddCallback(driver);
     } else {
       mDriver = new SystemClockDriver(this);
     }
   } else {
     mDriver = new OfflineClockDriver(this, MEDIA_GRAPH_TARGET_PERIOD_MS);
@@ -2955,47 +2954,55 @@ MediaStreamGraphShutdownObserver::Observ
     gGraphs.EnumerateRead(ForceShutdownEnumerator, nullptr);
     nsContentUtils::UnregisterShutdownObserver(this);
     gShutdownObserverRegistered = false;
   }
   return NS_OK;
 }
 
 MediaStreamGraph*
-MediaStreamGraph::GetInstance(bool aStartWithAudioDriver,
+MediaStreamGraph::GetInstance(MediaStreamGraph::GraphDriverType aGraphDriverRequested,
                               dom::AudioChannel aChannel)
 {
   NS_ASSERTION(NS_IsMainThread(), "Main thread only");
 
   uint32_t channel = static_cast<uint32_t>(aChannel);
   MediaStreamGraphImpl* graph = nullptr;
 
   if (!gGraphs.Get(channel, &graph)) {
     if (!gShutdownObserverRegistered) {
       gShutdownObserverRegistered = true;
       nsContentUtils::RegisterShutdownObserver(new MediaStreamGraphShutdownObserver());
     }
 
     CubebUtils::InitPreferredSampleRate();
 
-    graph = new MediaStreamGraphImpl(true, CubebUtils::PreferredSampleRate(), aStartWithAudioDriver, aChannel);
+    graph = new MediaStreamGraphImpl(aGraphDriverRequested,
+                                     CubebUtils::PreferredSampleRate(),
+                                     aChannel);
+
     gGraphs.Put(channel, graph);
 
-    STREAM_LOG(LogLevel::Debug, ("Starting up MediaStreamGraph %p", graph));
+    STREAM_LOG(LogLevel::Debug,
+        ("Starting up MediaStreamGraph %p for channel %s",
+         graph, AudioChannelValues::strings[channel]));
   }
 
   return graph;
 }
 
 MediaStreamGraph*
 MediaStreamGraph::CreateNonRealtimeInstance(TrackRate aSampleRate)
 {
   NS_ASSERTION(NS_IsMainThread(), "Main thread only");
 
-  MediaStreamGraphImpl* graph = new MediaStreamGraphImpl(false, aSampleRate);
+  MediaStreamGraphImpl* graph =
+    new MediaStreamGraphImpl(OFFLINE_THREAD_DRIVER,
+                             aSampleRate,
+                             AudioChannel::Normal);
 
   STREAM_LOG(LogLevel::Debug, ("Starting up Offline MediaStreamGraph %p", graph));
 
   return graph;
 }
 
 void
 MediaStreamGraph::DestroyNonRealtimeInstance(MediaStreamGraph* aGraph)

--- a/dom/media/MediaStreamGraph.h
+++ b/dom/media/MediaStreamGraph.h
@@ -1190,32 +1190,43 @@ protected:
   bool mAutofinish;
   // After UpdateStreamOrder(), mCycleMarker is either 0 or 1 to indicate
   // whether this stream is in a muted cycle.  During ordering it can contain
   // other marker values - see MediaStreamGraphImpl::UpdateStreamOrder().
   uint32_t mCycleMarker;
 };
 
 /**
- * Initially, at least, we will have a singleton MediaStreamGraph per
- * process.  Each OfflineAudioContext object creates its own MediaStreamGraph
- * object too.
+ * There can be multiple MediaStreamGraph per process: one per AudioChannel.
+ * Additionaly, each OfflineAudioContext object creates its own MediaStreamGraph
+ * object too..
  */
 class MediaStreamGraph
 {
 public:
+
   // We ensure that the graph current time advances in multiples of
   // IdealAudioBlockSize()/AudioStream::PreferredSampleRate(). A stream that
   // never blocks and has a track with the ideal audio rate will produce audio
   // in multiples of the block size.
   //
 
+  // Initializing an graph that outputs audio can be quite long on some
+  // platforms. Code that want to output audio at some point can express the
+  // fact that they will need an audio stream at some point by passing
+  // AUDIO_THREAD_DRIVER when getting an instance of MediaStreamGraph, so that
+  // the graph starts with the right driver.
+  enum GraphDriverType {
+    AUDIO_THREAD_DRIVER,
+    SYSTEM_THREAD_DRIVER,
+    OFFLINE_THREAD_DRIVER
+  };
   // Main thread only
-  static MediaStreamGraph* GetInstance(bool aStartWithAudioDriver = false,
-                                       dom::AudioChannel aChannel = dom::AudioChannel::Normal);
+  static MediaStreamGraph* GetInstance(GraphDriverType aGraphDriverRequested,
+                                       dom::AudioChannel aChannel);
   static MediaStreamGraph* CreateNonRealtimeInstance(TrackRate aSampleRate);
   // Idempotent
   static void DestroyNonRealtimeInstance(MediaStreamGraph* aGraph);
 
   // Control API.
   /**
    * Create a stream that a media decoder (or some other source of
    * media data, such as a camera) can write to.

--- a/dom/media/MediaStreamGraphImpl.h
+++ b/dom/media/MediaStreamGraphImpl.h
@@ -88,26 +88,26 @@ public:
 class MediaStreamGraphImpl : public MediaStreamGraph,
                              public nsIMemoryReporter
 {
 public:
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_DECL_NSIMEMORYREPORTER
 
   /**
-   * Set aRealtime to true in order to create a MediaStreamGraph which provides
-   * support for real-time audio and video.  Set it to false in order to create
-   * a non-realtime instance which just churns through its inputs and produces
-   * output.  Those objects currently only support audio, and are used to
-   * implement OfflineAudioContext.  They do not support MediaStream inputs.
+   * Use aGraphDriverRequested with SYSTEM_THREAD_DRIVER or AUDIO_THREAD_DRIVER
+   * to create a MediaStreamGraph which provides support for real-time audio
+   * and/or video.  Set it to false in order to create a non-realtime instance
+   * which just churns through its inputs and produces output.  Those objects
+   * currently only support audio, and are used to implement
+   * OfflineAudioContext.  They do not support MediaStream inputs.
    */
-  explicit MediaStreamGraphImpl(bool aRealtime,
+  explicit MediaStreamGraphImpl(GraphDriverType aGraphDriverRequested,
                                 TrackRate aSampleRate,
-                                bool aStartWithAudioDriver = false,
-                                dom::AudioChannel aChannel = dom::AudioChannel::Normal);
+                                dom::AudioChannel aChannel);
 
   /**
    * Unregisters memory reporting and deletes this instance. This should be
    * called instead of calling the destructor directly.
    */
   void Destroy();
 
   // Main thread only.

--- a/dom/media/android/moz.build
+++ b/dom/media/android/moz.build
@@ -20,10 +20,8 @@ UNIFIED_SOURCES += [
 ]
 
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/html',
 ]
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/dom/media/apple/moz.build
+++ b/dom/media/apple/moz.build
@@ -9,13 +9,11 @@ EXPORTS += [
     'AppleMP3Reader.h',
 ]
 
 UNIFIED_SOURCES += [
     'AppleDecoder.cpp',
     'AppleMP3Reader.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'
 
 OS_LIBS += ['-framework AudioToolbox']

--- a/dom/media/bridge/moz.build
+++ b/dom/media/bridge/moz.build
@@ -21,10 +21,8 @@ LOCAL_INCLUDES += [
     '/media/webrtc/',
     '/media/webrtc/signaling/src/common/time_profiling',
     '/media/webrtc/signaling/src/media-conduit',
     '/media/webrtc/signaling/src/mediapipeline',
     '/media/webrtc/signaling/src/peerconnection',
 ]
 
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/dom/media/compiledtest/moz.build
+++ b/dom/media/compiledtest/moz.build
@@ -4,17 +4,15 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 GeckoCppUnitTests([
     'TestAudioBuffers',
     'TestAudioMixer'
 ])
 
-FAIL_ON_WARNINGS = True
-
 LOCAL_INCLUDES += [
     '..',
 ]
 
 USE_LIBS += [
     'lgpllibs',
 ]

--- a/dom/media/directshow/moz.build
+++ b/dom/media/directshow/moz.build
@@ -30,14 +30,12 @@ SOURCES += [
 if not CONFIG['MOZ_WEBRTC']:
     SOURCES += [
         '/media/webrtc/trunk/webrtc/modules/video_capture/windows/BaseFilter.cpp',
         '/media/webrtc/trunk/webrtc/modules/video_capture/windows/BaseInputPin.cpp',
         '/media/webrtc/trunk/webrtc/modules/video_capture/windows/BasePin.cpp',
         '/media/webrtc/trunk/webrtc/modules/video_capture/windows/MediaType.cpp',
     ]
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/media/webrtc/trunk/webrtc/modules/video_capture/windows',
 ]

--- a/dom/media/eme/EMEUtils.cpp
+++ b/dom/media/eme/EMEUtils.cpp
@@ -84,17 +84,16 @@ ParseKeySystem(const nsAString& aExpecte
   }
   aOutCDMVersion = version;
 
   return true;
 }
 
 static const char16_t* sKeySystems[] = {
   MOZ_UTF16("org.w3.clearkey"),
-  MOZ_UTF16("com.adobe.access"),
   MOZ_UTF16("com.adobe.primetime"),
 };
 
 bool
 ParseKeySystem(const nsAString& aInputKeySystem,
                nsAString& aOutKeySystem,
                int32_t& aOutCDMVersion)
 {
@@ -119,9 +118,19 @@ LogToBrowserConsole(const nsAString& aMs
   if (!console) {
     NS_WARNING("Failed to log message to console.");
     return;
   }
   nsAutoString msg(aMsg);
   console->LogStringMessage(msg.get());
 }
 
+void
+ConstructKeySystem(const nsAString& aKeySystem,
+                   const nsAString& aCDMVersion,
+                   nsAString& aOutKeySystem)
+{
+  aOutKeySystem.Append(aKeySystem);
+  aOutKeySystem.AppendLiteral(".");
+  aOutKeySystem.Append(aCDMVersion);
+}
+
 } // namespace mozilla

--- a/dom/media/eme/EMEUtils.h
+++ b/dom/media/eme/EMEUtils.h
@@ -49,11 +49,16 @@ namespace mozilla {
 // if present. If it was not present, aOutMinCDMVersion is NO_CDM_VERSION.
 bool ParseKeySystem(const nsAString& aKeySystem,
                     nsAString& aOutKeySystem,
                     int32_t& aOutMinCDMVersion);
 
 void
 LogToBrowserConsole(const nsAString& aMsg);
 
+void
+ConstructKeySystem(const nsAString& aKeySystem,
+                   const nsAString& aCDMVersion,
+                   nsAString& aOutKeySystem);
+
 } // namespace mozilla
 
 #endif // EME_LOG_H_

--- a/dom/media/eme/GMPVideoDecoderTrialCreator.h
+++ b/dom/media/eme/GMPVideoDecoderTrialCreator.h
@@ -85,17 +85,17 @@ private:
     Pending = 0,
     Succeeded = 1,
     Failed = 2,
   };
 
   static TrialCreateState GetCreateTrialState(const nsAString& aKeySystem);
 
   struct TrialCreateData {
-    TrialCreateData(const nsAString& aKeySystem)
+    explicit TrialCreateData(const nsAString& aKeySystem)
       : mKeySystem(aKeySystem)
       , mStatus(GetCreateTrialState(aKeySystem))
     {}
     ~TrialCreateData() {}
     const nsString mKeySystem;
     nsRefPtr<TestGMPVideoDecoder> mTest;
     nsTArray<nsRefPtr<AbstractPromiseLike>> mPending;
     TrialCreateState mStatus;
@@ -136,17 +136,17 @@ public:
   virtual void Error(GMPErr aErr) override;
   virtual void Terminated() override;
 
   void ActorCreated(GMPVideoDecoderProxy* aGMP, GMPVideoHost* aHost); // Main thread.
 
   class Callback : public GetGMPVideoDecoderCallback
   {
   public:
-    Callback(TestGMPVideoDecoder* aInstance)
+    explicit Callback(TestGMPVideoDecoder* aInstance)
       : mInstance(aInstance)
     {}
     ~Callback() {}
     void Done(GMPVideoDecoderProxy* aGMP, GMPVideoHost* aHost) override;
   private:
     nsRefPtr<TestGMPVideoDecoder> mInstance;
   };
 

--- a/dom/media/eme/MediaKeySession.cpp
+++ b/dom/media/eme/MediaKeySession.cpp
@@ -38,21 +38,23 @@ NS_IMPL_RELEASE_INHERITED(MediaKeySessio
 // Count of number of instances. Used to give each instance a
 // unique token.
 static uint32_t sMediaKeySessionNum = 0;
 
 MediaKeySession::MediaKeySession(JSContext* aCx,
                                  nsPIDOMWindow* aParent,
                                  MediaKeys* aKeys,
                                  const nsAString& aKeySystem,
+                                 const nsAString& aCDMVersion,
                                  SessionType aSessionType,
                                  ErrorResult& aRv)
   : DOMEventTargetHelper(aParent)
   , mKeys(aKeys)
   , mKeySystem(aKeySystem)
+  , mCDMVersion(aCDMVersion)
   , mSessionType(aSessionType)
   , mToken(sMediaKeySessionNum++)
   , mIsClosed(false)
   , mUninitialized(true)
   , mKeyStatusMap(new MediaKeyStatusMap(aCx, aParent, aRv))
 {
   EME_LOG("MediaKeySession[%p,''] session Id set", this);
 
@@ -81,19 +83,19 @@ MediaKeySession::~MediaKeySession()
 
 MediaKeyError*
 MediaKeySession::GetError() const
 {
   return mMediaKeyError;
 }
 
 void
-MediaKeySession::GetKeySystem(nsString& aKeySystem) const
+MediaKeySession::GetKeySystem(nsString& aOutKeySystem) const
 {
-  aKeySystem = mKeySystem;
+  ConstructKeySystem(mKeySystem, mCDMVersion, aOutKeySystem);
 }
 
 void
 MediaKeySession::GetSessionId(nsString& aSessionId) const
 {
   aSessionId = GetSessionId();
 }
 

--- a/dom/media/eme/MediaKeySession.h
+++ b/dom/media/eme/MediaKeySession.h
@@ -36,16 +36,17 @@ public:
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MediaKeySession,
                                            DOMEventTargetHelper)
 public:
   MediaKeySession(JSContext* aCx,
                   nsPIDOMWindow* aParent,
                   MediaKeys* aKeys,
                   const nsAString& aKeySystem,
+                  const nsAString& aCDMVersion,
                   SessionType aSessionType,
                   ErrorResult& aRv);
 
   void SetSessionId(const nsAString& aSessionId);
 
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
   // Mark this as resultNotAddRefed to return raw pointers
@@ -101,16 +102,17 @@ private:
   already_AddRefed<DetailedPromise> MakePromise(ErrorResult& aRv,
                                                 const nsACString& aName);
 
   nsRefPtr<DetailedPromise> mClosed;
 
   nsRefPtr<MediaKeyError> mMediaKeyError;
   nsRefPtr<MediaKeys> mKeys;
   const nsString mKeySystem;
+  const nsString mCDMVersion;
   nsString mSessionId;
   const SessionType mSessionType;
   const uint32_t mToken;
   bool mIsClosed;
   bool mUninitialized;
   nsRefPtr<MediaKeyStatusMap> mKeyStatusMap;
 };
 

--- a/dom/media/eme/MediaKeySystemAccess.cpp
+++ b/dom/media/eme/MediaKeySystemAccess.cpp
@@ -10,45 +10,54 @@
 #include "nsContentTypeParser.h"
 #ifdef MOZ_FMP4
 #include "MP4Decoder.h"
 #endif
 #ifdef XP_WIN
 #include "mozilla/WindowsVersion.h"
 #include "WMFDecoderModule.h"
 #endif
+#ifdef XP_MACOSX
+#include "nsCocoaFeatures.h"
+#endif
 #include "nsContentCID.h"
 #include "nsServiceManagerUtils.h"
 #include "mozIGeckoMediaPluginService.h"
 #include "VideoUtils.h"
 #include "mozilla/Services.h"
 #include "nsIObserverService.h"
 #include "mozilla/EMEUtils.h"
 #include "GMPUtils.h"
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsDirectoryServiceUtils.h"
 #include "nsDirectoryServiceDefs.h"
 #include "nsXULAppAPI.h"
 
+#if defined(XP_WIN) || defined(XP_MACOSX)
+#define PRIMETIME_EME_SUPPORTED 1
+#endif
+
 namespace mozilla {
 namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(MediaKeySystemAccess,
                                       mParent)
 NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeySystemAccess)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeySystemAccess)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeySystemAccess)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
 MediaKeySystemAccess::MediaKeySystemAccess(nsPIDOMWindow* aParent,
-                                           const nsAString& aKeySystem)
+                                           const nsAString& aKeySystem,
+                                           const nsAString& aCDMVersion)
   : mParent(aParent)
   , mKeySystem(aKeySystem)
+  , mCDMVersion(aCDMVersion)
 {
 }
 
 MediaKeySystemAccess::~MediaKeySystemAccess()
 {
 }
 
 JSObject*
@@ -59,25 +68,25 @@ MediaKeySystemAccess::WrapObject(JSConte
 
 nsPIDOMWindow*
 MediaKeySystemAccess::GetParentObject() const
 {
   return mParent;
 }
 
 void
-MediaKeySystemAccess::GetKeySystem(nsString& aRetVal) const
+MediaKeySystemAccess::GetKeySystem(nsString& aOutKeySystem) const
 {
-  aRetVal = mKeySystem;
+  ConstructKeySystem(mKeySystem, mCDMVersion, aOutKeySystem);
 }
 
 already_AddRefed<Promise>
 MediaKeySystemAccess::CreateMediaKeys(ErrorResult& aRv)
 {
-  nsRefPtr<MediaKeys> keys(new MediaKeys(mParent, mKeySystem));
+  nsRefPtr<MediaKeys> keys(new MediaKeys(mParent, mKeySystem, mCDMVersion));
   return keys->Init(aRv);
 }
 
 static bool
 HaveGMPFor(mozIGeckoMediaPluginService* aGMPService,
            const nsCString& aKeySystem,
            const nsCString& aAPI,
            const nsCString& aTag = EmptyCString())
@@ -143,38 +152,40 @@ AdobePluginVoucherExists(const nsACStrin
   return AdobePluginFileExists(aVersionStr, NS_LITERAL_STRING("eme-adobe.voucher"));
 }
 #endif
 
 static MediaKeySystemStatus
 EnsureMinCDMVersion(mozIGeckoMediaPluginService* aGMPService,
                     const nsAString& aKeySystem,
                     int32_t aMinCdmVersion,
-                    nsACString& aOutMessage)
+                    nsACString& aOutMessage,
+                    nsACString& aOutCdmVersion)
 {
   nsTArray<nsCString> tags;
   tags.AppendElement(NS_ConvertUTF16toUTF8(aKeySystem));
   bool hasPlugin;
   nsAutoCString versionStr;
   if (NS_FAILED(aGMPService->GetPluginVersionForAPI(NS_LITERAL_CSTRING(GMP_API_DECRYPTOR),
                                                     &tags,
                                                     &hasPlugin,
                                                     versionStr))) {
     aOutMessage = NS_LITERAL_CSTRING("GetPluginVersionForAPI failed");
     return MediaKeySystemStatus::Error;
   }
 
+  aOutCdmVersion = versionStr;
+
   if (!hasPlugin) {
     aOutMessage = NS_LITERAL_CSTRING("CDM is not installed");
     return MediaKeySystemStatus::Cdm_not_installed;
   }
 
 #ifdef XP_WIN
-  if (aKeySystem.EqualsLiteral("com.adobe.access") ||
-      aKeySystem.EqualsLiteral("com.adobe.primetime")) {
+  if (aKeySystem.EqualsLiteral("com.adobe.primetime")) {
     // Verify that anti-virus hasn't "helpfully" deleted the Adobe GMP DLL,
     // as we suspect may happen (Bug 1160382).
     bool somethingMissing = false;
     if (!AdobePluginDLLExists(versionStr)) {
       aOutMessage = NS_LITERAL_CSTRING("Adobe DLL was expected to be on disk but was not");
       somethingMissing = true;
     }
     if (!AdobePluginVoucherExists(versionStr)) {
@@ -202,54 +213,61 @@ EnsureMinCDMVersion(mozIGeckoMediaPlugin
 
   return MediaKeySystemStatus::Available;
 }
 
 /* static */
 MediaKeySystemStatus
 MediaKeySystemAccess::GetKeySystemStatus(const nsAString& aKeySystem,
                                          int32_t aMinCdmVersion,
-                                         nsACString& aOutMessage)
+                                         nsACString& aOutMessage,
+                                         nsACString& aOutCdmVersion)
 {
   MOZ_ASSERT(Preferences::GetBool("media.eme.enabled", false));
   nsCOMPtr<mozIGeckoMediaPluginService> mps =
     do_GetService("@mozilla.org/gecko-media-plugin-service;1");
   if (NS_WARN_IF(!mps)) {
     aOutMessage = NS_LITERAL_CSTRING("Failed to get GMP service");
     return MediaKeySystemStatus::Error;
   }
 
   if (aKeySystem.EqualsLiteral("org.w3.clearkey")) {
     if (!Preferences::GetBool("media.eme.clearkey.enabled", true)) {
       aOutMessage = NS_LITERAL_CSTRING("ClearKey was disabled");
       return MediaKeySystemStatus::Cdm_disabled;
     }
-    return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage);
+    return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage, aOutCdmVersion);
   }
 
+#ifdef PRIMETIME_EME_SUPPORTED
+  if (aKeySystem.EqualsLiteral("com.adobe.primetime")) {
+    if (!Preferences::GetBool("media.gmp-eme-adobe.enabled", false)) {
+      aOutMessage = NS_LITERAL_CSTRING("Adobe EME disabled");
+      return MediaKeySystemStatus::Cdm_disabled;
+    }
 #ifdef XP_WIN
-  if ((aKeySystem.EqualsLiteral("com.adobe.access") ||
-       aKeySystem.EqualsLiteral("com.adobe.primetime"))) {
     // Win Vista and later only.
     if (!IsVistaOrLater()) {
       aOutMessage = NS_LITERAL_CSTRING("Minimum Windows version not met for Adobe EME");
       return MediaKeySystemStatus::Cdm_not_supported;
     }
-    if (!Preferences::GetBool("media.gmp-eme-adobe.enabled", false)) {
-      aOutMessage = NS_LITERAL_CSTRING("Adobe EME disabled");
-      return MediaKeySystemStatus::Cdm_disabled;
+#endif
+#ifdef XP_MACOSX
+    if (!nsCocoaFeatures::OnLionOrLater()) {
+      aOutMessage = NS_LITERAL_CSTRING("Minimum MacOSX version not met for Adobe EME");
+      return MediaKeySystemStatus::Cdm_not_supported;
     }
+#endif
     if (!EMEVoucherFileExists()) {
-      // The system doesn't have the codecs that Adobe EME relies
-      // on installed, or doesn't have a voucher for the plugin-container.
+      // Gecko doesn't have a voucher file for the plugin-container.
       // Adobe EME isn't going to work, so don't advertise that it will.
       aOutMessage = NS_LITERAL_CSTRING("Plugin-container voucher not present");
       return MediaKeySystemStatus::Cdm_not_supported;
     }
-    return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage);
+    return EnsureMinCDMVersion(mps, aKeySystem, aMinCdmVersion, aOutMessage, aOutCdmVersion);
   }
 #endif
 
   return MediaKeySystemStatus::Cdm_not_supported;
 }
 
 static bool
 IsPlayableWithGMP(mozIGeckoMediaPluginService* aGMPS,

--- a/dom/media/eme/MediaKeySystemAccess.h
+++ b/dom/media/eme/MediaKeySystemAccess.h
@@ -25,17 +25,18 @@ class MediaKeySystemAccess final : publi
                                    public nsWrapperCache
 {
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaKeySystemAccess)
 
 public:
   explicit MediaKeySystemAccess(nsPIDOMWindow* aParent,
-                                const nsAString& aKeySystem);
+                                const nsAString& aKeySystem,
+                                const nsAString& aCDMVersion);
 
 protected:
   ~MediaKeySystemAccess();
 
 public:
   nsPIDOMWindow* GetParentObject() const;
 
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
@@ -43,26 +44,28 @@ public:
   void GetKeySystem(nsString& aRetVal) const;
 
   already_AddRefed<Promise> CreateMediaKeys(ErrorResult& aRv);
 
 
 
   static MediaKeySystemStatus GetKeySystemStatus(const nsAString& aKeySystem,
                                                  int32_t aMinCdmVersion,
-                                                 nsACString& aOutExceptionMessage);
+                                                 nsACString& aOutExceptionMessage,
+                                                 nsACString& aOutCdmVersion);
 
   static bool IsSupported(const nsAString& aKeySystem,
                           const Sequence<MediaKeySystemOptions>& aOptions);
 
   static void NotifyObservers(nsIDOMWindow* aWindow,
                               const nsAString& aKeySystem,
                               MediaKeySystemStatus aStatus);
 
 private:
   nsCOMPtr<nsPIDOMWindow> mParent;
   const nsString mKeySystem;
+  const nsString mCDMVersion;
 };
 
 } // namespace dom
 } // namespace mozilla
 
 #endif // mozilla_dom_MediaKeySystemAccess_h

--- a/dom/media/eme/MediaKeySystemAccessManager.cpp
+++ b/dom/media/eme/MediaKeySystemAccessManager.cpp
@@ -8,16 +8,19 @@
 #include "nsServiceManagerUtils.h"
 #include "nsComponentManagerUtils.h"
 #include "nsIObserverService.h"
 #include "mozilla/Services.h"
 #include "mozilla/DetailedPromise.h"
 #ifdef XP_WIN
 #include "mozilla/WindowsVersion.h"
 #endif
+#ifdef XP_MACOSX
+#include "nsCocoaFeatures.h"
+#endif
 #include "nsPrintfCString.h"
 
 namespace mozilla {
 namespace dom {
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeySystemAccessManager)
   NS_INTERFACE_MAP_ENTRY(nsISupports)
   NS_INTERFACE_MAP_ENTRY(nsIObserver)
@@ -69,16 +72,33 @@ MediaKeySystemAccessManager::Request(Det
                           NS_LITERAL_CSTRING("Invalid keysystem type or invalid options sequence"));
     return;
   }
   Sequence<MediaKeySystemOptions> optionsNotPassed;
   const auto& options = aOptions.WasPassed() ? aOptions.Value() : optionsNotPassed;
   Request(aPromise, aKeySystem, options, RequestType::Initial);
 }
 
+static bool
+ShouldTrialCreateGMP(const nsAString& aKeySystem)
+{
+  // Trial create where the CDM has a decoder;
+  // * ClearKey and Primetime on Windows Vista and later.
+  // * Primetime on MacOSX Lion and later.
+  return
+#ifdef XP_WIN
+    IsVistaOrLater();
+#elif defined(XP_MACOSX)
+    aKeySystem.EqualsLiteral("com.adobe.primetime") &&
+    nsCocoaFeatures::OnLionOrLater();
+#else
+    false;
+#endif
+}
+
 void
 MediaKeySystemAccessManager::Request(DetailedPromise* aPromise,
                                      const nsAString& aKeySystem,
                                      const Sequence<MediaKeySystemOptions>& aOptions,
                                      RequestType aType)
 {
   EME_LOG("MediaKeySystemAccessManager::Request %s", NS_ConvertUTF16toUTF8(aKeySystem).get());
   if (!Preferences::GetBool("media.eme.enabled", false)) {
@@ -102,24 +122,26 @@ MediaKeySystemAccessManager::Request(Det
     // to chrome to show a failure notice.
     MediaKeySystemAccess::NotifyObservers(mWindow, aKeySystem, MediaKeySystemStatus::Cdm_not_supported);
     aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
                           NS_LITERAL_CSTRING("Key system string is invalid, or key system is unsupported"));
     return;
   }
 
   nsAutoCString message;
+  nsAutoCString cdmVersion;
   MediaKeySystemStatus status =
-    MediaKeySystemAccess::GetKeySystemStatus(keySystem, minCdmVersion, message);
+    MediaKeySystemAccess::GetKeySystemStatus(keySystem, minCdmVersion, message, cdmVersion);
 
   nsPrintfCString msg("MediaKeySystemAccess::GetKeySystemStatus(%s, minVer=%d) "
-                      "result=%s msg='%s'",
+                      "result=%s version='%s' msg='%s'",
                       NS_ConvertUTF16toUTF8(keySystem).get(),
                       minCdmVersion,
                       MediaKeySystemStatusValues::strings[(size_t)status].value,
+                      cdmVersion.get(),
                       message.get());
   LogToBrowserConsole(NS_ConvertUTF8toUTF16(msg));
 
   if ((status == MediaKeySystemStatus::Cdm_not_installed ||
        status == MediaKeySystemStatus::Cdm_insufficient_version) &&
       keySystem.EqualsLiteral("com.adobe.primetime")) {
     // These are cases which could be resolved by downloading a new(er) CDM.
     // When we send the status to chrome, chrome's GMPProvider will attempt to
@@ -155,27 +177,25 @@ MediaKeySystemAccessManager::Request(Det
     }
     aPromise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
                           NS_LITERAL_CSTRING("GetKeySystemAccess failed"));
     return;
   }
 
   if (aOptions.IsEmpty() ||
       MediaKeySystemAccess::IsSupported(keySystem, aOptions)) {
-    nsRefPtr<MediaKeySystemAccess> access(new MediaKeySystemAccess(mWindow, keySystem));
-#ifdef XP_WIN
-    if (IsVistaOrLater()) {
-      // On Windows, ensure we have tried creating a GMPVideoDecoder for this
+    nsRefPtr<MediaKeySystemAccess> access(
+      new MediaKeySystemAccess(mWindow, keySystem, NS_ConvertUTF8toUTF16(cdmVersion)));
+   if (ShouldTrialCreateGMP(keySystem)) {
+      // Ensure we have tried creating a GMPVideoDecoder for this
       // keySystem, and that we can use it to decode. This ensures that we only
-      // report that we support this keySystem when the CDM us usable (i.e.
-      // all system libraries required are installed).
+      // report that we support this keySystem when the CDM us usable.
       mTrialCreator->MaybeAwaitTrialCreate(keySystem, access, aPromise, mWindow);
       return;
     }
-#endif
     aPromise->MaybeResolve(access);
     return;
   }
 
   aPromise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
                         NS_LITERAL_CSTRING("Key system is not supported"));
 }
 

--- a/dom/media/eme/MediaKeySystemAccessManager.h
+++ b/dom/media/eme/MediaKeySystemAccessManager.h
@@ -1,19 +1,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_dom_MediaKeySystemAccessManager_h
 #define mozilla_dom_MediaKeySystemAccessManager_h
 
 #include "mozilla/dom/MediaKeySystemAccess.h"
-#ifdef XP_WIN
 #include "mozilla/dom/GMPVideoDecoderTrialCreator.h"
-#endif
 #include "nsIObserver.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsISupportsImpl.h"
 #include "nsITimer.h"
 
 namespace mozilla {
 namespace dom {
 
@@ -74,17 +72,15 @@ private:
 
   void RetryRequest(PendingRequest& aRequest);
 
   nsTArray<PendingRequest> mRequests;
 
   nsCOMPtr<nsPIDOMWindow> mWindow;
   bool mAddedObservers;
 
-#ifdef XP_WIN
   nsRefPtr<GMPVideoDecoderTrialCreator> mTrialCreator;
-#endif
 };
 
 } // namespace dom
 } // namespace mozilla
 
 #endif

--- a/dom/media/eme/MediaKeys.cpp
+++ b/dom/media/eme/MediaKeys.cpp
@@ -42,19 +42,22 @@ NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Me
                                       mPendingSessions);
 NS_IMPL_CYCLE_COLLECTING_ADDREF(MediaKeys)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(MediaKeys)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MediaKeys)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
-MediaKeys::MediaKeys(nsPIDOMWindow* aParent, const nsAString& aKeySystem)
+MediaKeys::MediaKeys(nsPIDOMWindow* aParent,
+                     const nsAString& aKeySystem,
+                     const nsAString& aCDMVersion)
   : mParent(aParent)
   , mKeySystem(aKeySystem)
+  , mCDMVersion(aCDMVersion)
   , mCreatePromiseId(0)
 {
   EME_LOG("MediaKeys[%p] constructed keySystem=%s",
           this, NS_ConvertUTF16toUTF8(mKeySystem).get());
 }
 
 static PLDHashOperator
 RejectPromises(const uint32_t& aKey,
@@ -134,19 +137,19 @@ MediaKeys::GetParentObject() const
 
 JSObject*
 MediaKeys::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 {
   return MediaKeysBinding::Wrap(aCx, this, aGivenProto);
 }
 
 void
-MediaKeys::GetKeySystem(nsString& retval) const
+MediaKeys::GetKeySystem(nsString& aOutKeySystem) const
 {
-  retval = mKeySystem;
+  ConstructKeySystem(mKeySystem, mCDMVersion, aOutKeySystem);
 }
 
 already_AddRefed<DetailedPromise>
 MediaKeys::SetServerCertificate(const ArrayBufferViewOrArrayBuffer& aCert, ErrorResult& aRv)
 {
   nsRefPtr<DetailedPromise> promise(MakePromise(aRv,
     NS_LITERAL_CSTRING("MediaKeys.setServerCertificate")));
   if (aRv.Failed()) {
@@ -428,16 +431,17 @@ MediaKeys::CreateSession(JSContext* aCx,
   }
 
   EME_LOG("MediaKeys[%p] Creating session", this);
 
   nsRefPtr<MediaKeySession> session = new MediaKeySession(aCx,
                                                           GetParentObject(),
                                                           this,
                                                           mKeySystem,
+                                                          mCDMVersion,
                                                           aSessionType,
                                                           aRv);
 
   if (aRv.Failed()) {
     return nullptr;
   }
 
   // Add session to the set of sessions awaiting their sessionId being ready.

--- a/dom/media/eme/MediaKeys.h
+++ b/dom/media/eme/MediaKeys.h
@@ -47,17 +47,17 @@ class MediaKeys final : public nsISuppor
                         public nsWrapperCache
 {
   ~MediaKeys();
 
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaKeys)
 
-  MediaKeys(nsPIDOMWindow* aParentWindow, const nsAString& aKeySystem);
+  MediaKeys(nsPIDOMWindow* aParentWindow, const nsAString& aKeySystem, const nsAString& aCDMVersion);
 
   already_AddRefed<DetailedPromise> Init(ErrorResult& aRv);
 
   nsPIDOMWindow* GetParentObject() const;
 
   virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
   nsresult Bind(HTMLMediaElement* aElement);
@@ -132,17 +132,18 @@ private:
 
   // Owning ref to proxy. The proxy has a weak reference back to the MediaKeys,
   // and the MediaKeys destructor clears the proxy's reference to the MediaKeys.
   nsRefPtr<CDMProxy> mProxy;
 
   nsRefPtr<HTMLMediaElement> mElement;
 
   nsCOMPtr<nsPIDOMWindow> mParent;
-  nsString mKeySystem;
+  const nsString mKeySystem;
+  const nsString mCDMVersion;
   nsCString mNodeId;
   KeySessionHashMap mKeySessions;
   PromiseHashMap mPromises;
   PendingKeySessionsHashMap mPendingSessions;
   PromiseId mCreatePromiseId;
 
   nsRefPtr<nsIPrincipal> mPrincipal;
   nsRefPtr<nsIPrincipal> mTopLevelPrincipal;

--- a/dom/media/eme/moz.build
+++ b/dom/media/eme/moz.build
@@ -1,15 +1,16 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # vim: set filetype=python:
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 EXPORTS.mozilla.dom += [
+    'GMPVideoDecoderTrialCreator.h',
     'MediaEncryptedEvent.h',
     'MediaKeyError.h',
     'MediaKeyMessageEvent.h',
     'MediaKeys.h',
     'MediaKeySession.h',
     'MediaKeyStatusMap.h',
     'MediaKeySystemAccess.h',
     'MediaKeySystemAccessManager.h',
@@ -24,29 +25,20 @@ EXPORTS.mozilla += [
 ]
 
 UNIFIED_SOURCES += [
     'CDMCallbackProxy.cpp',
     'CDMCaps.cpp',
     'CDMProxy.cpp',
     'DetailedPromise.cpp',
     'EMEUtils.cpp',
+    'GMPVideoDecoderTrialCreator.cpp',
     'MediaEncryptedEvent.cpp',
     'MediaKeyError.cpp',
     'MediaKeyMessageEvent.cpp',
     'MediaKeys.cpp',
     'MediaKeySession.cpp',
     'MediaKeyStatusMap.cpp',
     'MediaKeySystemAccess.cpp',
     'MediaKeySystemAccessManager.cpp',
 ]
 
-if CONFIG['OS_ARCH'] == 'WINNT':
-    UNIFIED_SOURCES += [
-        'GMPVideoDecoderTrialCreator.cpp',
-    ]
-    EXPORTS.mozilla.dom += [
-        'GMPVideoDecoderTrialCreator.h',
-    ]
-
 FINAL_LIBRARY = 'xul'
-
-FAIL_ON_WARNINGS = True

--- a/dom/media/encoder/fmp4_muxer/moz.build
+++ b/dom/media/encoder/fmp4_muxer/moz.build
@@ -13,11 +13,9 @@ UNIFIED_SOURCES += [
     'AMRBox.cpp',
     'AVCBox.cpp',
     'ISOControl.cpp',
     'ISOMediaBoxes.cpp',
     'ISOMediaWriter.cpp',
     'MP4ESDS.cpp',
 ]
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'

--- a/dom/media/encoder/moz.build
+++ b/dom/media/encoder/moz.build
@@ -33,18 +33,16 @@ if CONFIG['MOZ_WEBM_ENCODER']:
     EXPORTS += ['VorbisTrackEncoder.h',
                 'VP8TrackEncoder.h',
     ]
     UNIFIED_SOURCES += ['VorbisTrackEncoder.cpp',
                         'VP8TrackEncoder.cpp',
     ]
     LOCAL_INCLUDES += ['/media/libyuv/include']
 
-FAIL_ON_WARNINGS = True
-
 FINAL_LIBRARY = 'xul'
 
 # These includes are from Android JB, for use of MediaCodec.
 LOCAL_INCLUDES += ['/ipc/chromium/src']
 CXXFLAGS += [
     '-I%s/%s' % (CONFIG['ANDROID_SOURCE'], d) for d in [
         'frameworks/native/opengl/include',
         'frameworks/native/include',