--- a/caps/moz.build
+++ b/caps/moz.build
@@ -25,18 +25,16 @@ UNIFIED_SOURCES += [
     'nsJSPrincipals.cpp',
     'nsNullPrincipal.cpp',
     'nsNullPrincipalURI.cpp',
     'nsPrincipal.cpp',
     'nsScriptSecurityManager.cpp',
     'nsSystemPrincipal.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
     '/js/xpconnect/src',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

--- a/chrome/moz.build
+++ b/chrome/moz.build
@@ -19,18 +19,16 @@ EXPORTS.mozilla.chrome += [
 
 UNIFIED_SOURCES += [
     'nsChromeProtocolHandler.cpp',
     'nsChromeRegistry.cpp',
     'nsChromeRegistryChrome.cpp',
     'nsChromeRegistryContent.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 GENERATED_INCLUDES += [
     '/xpcom',
 ]
 

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

--- a/docshell/shistory/src/moz.build
+++ b/docshell/shistory/src/moz.build
@@ -12,15 +12,13 @@ UNIFIED_SOURCES += [
     'nsSHEntry.cpp',
     'nsSHEntryShared.cpp',
     'nsSHistory.cpp',
     'nsSHTransaction.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/docshell/base',
 ]
 
 FINAL_LIBRARY = 'xul'

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

--- a/dom/base/moz.build
+++ b/dom/base/moz.build
@@ -397,18 +397,16 @@ if CONFIG['MOZ_BUILD_APP'] != 'mobile/an
 
 EXTRA_JS_MODULES += [
     'DOMRequestHelper.jsm',
     'IndexedDBHelper.jsm',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '../battery',
     '../bluetooth',
     '../events',
     '../media',
     '../network',
     '../time',
     '/caps',

--- a/dom/bindings/moz.build
+++ b/dom/bindings/moz.build
@@ -37,18 +37,16 @@ EXPORTS.mozilla.dom += [
     'StructuredClone.h',
     'ToJSValue.h',
     'TypedArray.h',
     'UnionMember.h',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/battery',
     '/dom/bluetooth',
     '/dom/camera',
     '/dom/canvas',
     '/dom/geolocation',
     '/dom/html',

--- a/dom/canvas/moz.build
+++ b/dom/canvas/moz.build
@@ -128,18 +128,16 @@ UNIFIED_SOURCES += [
     'WebGLVertexArrayGL.cpp',
 ]
 LOCAL_INCLUDES += [
     '/js/xpconnect/wrappers',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/html',
     '/dom/svg',
     '/dom/xul',

--- a/dom/events/moz.build
+++ b/dom/events/moz.build
@@ -121,18 +121,16 @@ SOURCES += [
     'EventStateManager.cpp',
 ]
 
 if CONFIG['MOZ_WEBSPEECH']:
     UNIFIED_SOURCES += ['SpeechRecognitionError.cpp']
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = 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
@@ -28,10 +28,9 @@ UNIFIED_SOURCES += [
 
 LOCAL_INCLUDES += [
     '../workers',
     # For nsDataHandler.h
     '/netwerk/protocol/data',
 ]
 
 FAIL_ON_WARNINGS = True
-MSVC_ENABLE_PGO = True
 FINAL_LIBRARY = 'xul'

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

--- a/dom/media/moz.build
+++ b/dom/media/moz.build
@@ -263,18 +263,16 @@ EXTRA_COMPONENTS += [
 EXTRA_JS_MODULES.media += [
     'IdpSandbox.jsm',
     'PeerConnectionIdp.jsm',
     'RTCStatsReport.jsm',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/caps',
     '/dom/base',
     '/dom/camera',
     '/layout/generic',
     '/layout/xul',
     '/netwerk/base',
 ]

--- a/dom/media/standalone/moz.build
+++ b/dom/media/standalone/moz.build
@@ -12,18 +12,16 @@ UNIFIED_SOURCES += [
     '../AudioSegment.cpp',
     '../SimpleImageBuffer.cpp',
     '../VideoSegment.cpp',
 ]
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     UNIFIED_SOURCES += ['../systemservices/OSXRunLoopSingleton.cpp']
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/caps',
     '/dom/base',
     '/dom/camera',
     '/layout/generic',
     '/layout/xul',
     '/netwerk/base',
 ]

--- a/dom/mobilemessage/moz.build
+++ b/dom/mobilemessage/moz.build
@@ -69,17 +69,15 @@ IPDL_SOURCES += [
     'ipc/PMobileMessageCursor.ipdl',
     'ipc/PSms.ipdl',
     'ipc/PSmsRequest.ipdl',
     'ipc/SmsTypes.ipdlh',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

--- a/dom/plugins/base/moz.build
+++ b/dom/plugins/base/moz.build
@@ -85,18 +85,16 @@ else:
         ]
     else:
         UNIFIED_SOURCES += [
             'nsPluginNativeWindow.cpp',
         ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/plugins/ipc',
     '/layout/generic',
     '/layout/xul',
     '/netwerk/base',
     '/widget',
     '/widget/android',

--- a/dom/quota/moz.build
+++ b/dom/quota/moz.build
@@ -32,17 +32,15 @@ EXPORTS.mozilla.dom.quota += [
 UNIFIED_SOURCES += [
     'FileStreams.cpp',
     'QuotaManager.cpp',
     'QuotaObject.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/caps',
 ]
 

--- a/dom/storage/moz.build
+++ b/dom/storage/moz.build
@@ -19,18 +19,16 @@ UNIFIED_SOURCES += [
 ]
 
 IPDL_SOURCES += [
     'PStorage.ipdl',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
 if CONFIG['ENABLE_TESTS']:

--- a/dom/workers/moz.build
+++ b/dom/workers/moz.build
@@ -86,18 +86,16 @@ UNIFIED_SOURCES += [
 ]
 
 IPDL_SOURCES += [
     'ServiceWorkerRegistrarTypes.ipdlh',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '../base',
     '../system',
     '/dom/base',
     '/xpcom/build',
     '/xpcom/threads',
 ]
 

--- a/dom/xbl/moz.build
+++ b/dom/xbl/moz.build
@@ -33,18 +33,16 @@ UNIFIED_SOURCES += [
     'nsXBLSerialize.cpp',
     'nsXBLService.cpp',
     'nsXBLWindowKeyHandler.cpp',
     'XBLChildrenElement.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/html',
     '/dom/xml',
     '/dom/xul',
     '/layout/style',
 ]
 

--- a/dom/xml/moz.build
+++ b/dom/xml/moz.build
@@ -28,18 +28,16 @@ UNIFIED_SOURCES += [
     'nsXMLPrettyPrinter.cpp',
     'ProcessingInstruction.cpp',
     'XMLDocument.cpp',
     'XMLStylesheetProcessingInstruction.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/caps',
     '/dom/base',
     '/dom/html',
     '/dom/xul',
     '/layout/style',

--- a/dom/xul/moz.build
+++ b/dom/xul/moz.build
@@ -37,18 +37,16 @@ XPIDL_SOURCES += [
 XPIDL_MODULE = 'xul'
 
 UNIFIED_SOURCES += [
     'nsXULControllers.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/docshell/base',
     '/dom/base',
     '/dom/html',
     '/dom/xbl',
     '/dom/xml',
     '/dom/xul/templates',
     '/layout/base',

--- a/dom/xul/templates/moz.build
+++ b/dom/xul/templates/moz.build
@@ -41,18 +41,16 @@ UNIFIED_SOURCES += [
     'nsXULTemplateQueryProcessorXML.cpp',
     'nsXULTemplateResultRDF.cpp',
     'nsXULTemplateResultSetRDF.cpp',
     'nsXULTemplateResultStorage.cpp',
     'nsXULTemplateResultXML.cpp',
     'nsXULTreeBuilder.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/xul',
     '/layout/xul/tree/',
 ]
 
 FINAL_LIBRARY = 'xul'
 

--- a/extensions/cookie/moz.build
+++ b/extensions/cookie/moz.build
@@ -17,15 +17,13 @@ UNIFIED_SOURCES += [
     'nsCookieModule.cpp',
     'nsCookiePermission.cpp',
     'nsCookiePromptService.cpp',
     'nsPermission.cpp',
     'nsPermissionManager.cpp',
     'nsPopupWindowManager.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 FAIL_ON_WARNINGS = True

--- a/gfx/2d/moz.build
+++ b/gfx/2d/moz.build
@@ -142,18 +142,16 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'coco
     ]
 
 if CONFIG['CPU_ARCH'] == 'arm' and CONFIG['BUILD_ARM_NEON']:
     SOURCES += ['BlurNEON.cpp']
     SOURCES['BlurNEON.cpp'].flags += ['-mfpu=neon']
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 for var in ('USE_CAIRO', 'MOZ2D_HAS_MOZ_CAIRO'):
     DEFINES[var] = True
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('android', 'gtk2', 'gtk3', 'gonk', 'qt'):

--- a/gfx/angle/moz.build
+++ b/gfx/angle/moz.build
@@ -122,18 +122,16 @@ DEFINES['EGLAPI'] = ""
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
     DIRS += [ 'src/libGLESv2', 'src/libEGL' ]
 
 EXPORTS.angle += [ 'include/GLSLANG/ShaderLang.h', 'include/GLSLANG/ShaderVars.h' ]
 EXPORTS.angle.KHR += [ 'include/KHR/khrplatform.h' ]
 
 LOCAL_INCLUDES += [ 'include', 'src' ]
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 # This tells ANGLE to build the translator with declspec(dllexport) on Windows
 # which we need to get these symbols exported from gkmedias
 DEFINES['COMPONENT_BUILD'] = True
 DEFINES['ANGLE_TRANSLATOR_IMPLEMENTATION'] = True
 

--- a/gfx/cairo/cairo/src/moz.build
+++ b/gfx/cairo/cairo/src/moz.build
@@ -180,18 +180,16 @@ UNIFIED_SOURCES += [
     'cairo-traps.c',
     'cairo-unicode.c',
     'cairo-user-font.c',
     'cairo-version.c',
     'cairo-wideint.c',
     'cairo.c',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 
 DEFINES['PACKAGE_VERSION'] = '"moz"'
 DEFINES['PACKAGE_BUGREPORT'] = '"http://bugzilla.mozilla.org/"'
 
 for var in ('CAIRO_HAS_PTHREAD', '_GNU_SOURCE'):
     DEFINES[var] = True
 

--- a/gfx/cairo/libpixman/src/moz.build
+++ b/gfx/cairo/libpixman/src/moz.build
@@ -53,18 +53,16 @@ SOURCES += [
     'pixman-region32.c',
     'pixman-solid-fill.c',
     'pixman-trap.c',
     'pixman-utils.c',
     'pixman-x86.c',
     'pixman.c',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 LOCAL_INCLUDES += [
     '../../cairo/src',
 ]
 
 if CONFIG['MOZ_USE_PTHREADS']:
     DEFINES['HAVE_PTHREAD_SETSPECIFIC'] = True
 

--- a/gfx/gl/moz.build
+++ b/gfx/gl/moz.build
@@ -137,18 +137,16 @@ UNIFIED_SOURCES += [
     'SharedSurfaceGL.cpp',
     'SurfaceTypes.cpp',
     'TextureGarbageBin.cpp',
     'TextureImageEGL.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['MOZ_D3DCOMPILER_VISTA_DLL']:
     DEFINES['MOZ_D3DCOMPILER_VISTA_DLL'] = CONFIG['MOZ_D3DCOMPILER_VISTA_DLL']
 if CONFIG['MOZ_D3DCOMPILER_XP_DLL']:
     DEFINES['MOZ_D3DCOMPILER_XP_DLL'] = CONFIG['MOZ_D3DCOMPILER_XP_DLL']

--- a/gfx/graphite2/src/moz.build
+++ b/gfx/graphite2/src/moz.build
@@ -50,18 +50,16 @@ UNIFIED_SOURCES += [
     'Segment.cpp',
     'Silf.cpp',
     'Slot.cpp',
     'Sparse.cpp',
     'TtfUtil.cpp',
     'UtfCodec.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
     DEFINES['GRAPHITE2_EXPORTING'] = True
 else:
     # tell graphite2 not to export symbols, we'll be linking it directly with
     # thebes
     DEFINES['GRAPHITE2_STATIC'] = True
 

--- a/gfx/harfbuzz/src/moz.build
+++ b/gfx/harfbuzz/src/moz.build
@@ -53,17 +53,15 @@ UNIFIED_SOURCES += [
     'hb-ot-tag.cc',
     'hb-set.cc',
     'hb-shape.cc',
     'hb-shaper.cc',
     'hb-unicode.cc',
     'hb-warning.cc',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 
 DEFINES['PACKAGE_VERSION'] = '"moz"'
 DEFINES['PACKAGE_BUGREPORT'] = '"http://bugzilla.mozilla.org/"'
 DEFINES['HAVE_OT'] = 1
 DEFINES['HB_NO_MT'] = True
 DEFINES['HB_NO_UNICODE_FUNCS'] = True

--- a/gfx/layers/moz.build
+++ b/gfx/layers/moz.build
@@ -359,18 +359,16 @@ IPDL_SOURCES = [
     'ipc/PLayer.ipdl',
     'ipc/PLayerTransaction.ipdl',
     'ipc/PSharedBufferManager.ipdl',
     'ipc/PTexture.ipdl',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '/docshell/base',  # for nsDocShell.h
     '/layout/base',    # for TouchManager.h
 ]
 
 FINAL_LIBRARY = 'xul'

--- a/gfx/ots/src/moz.build
+++ b/gfx/ots/src/moz.build
@@ -42,18 +42,16 @@ UNIFIED_SOURCES += [
     'ots.cc',
     'post.cc',
     'prep.cc',
     'vhea.cc',
     'vmtx.cc',
     'woff2.cc',
 ]
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'
 
 DEFINES['PACKAGE_VERSION'] = '"moz"'
 DEFINES['PACKAGE_BUGREPORT'] = '"http://bugzilla.mozilla.org/"'
 DEFINES['NOMINMAX'] = True

--- a/gfx/qcms/moz.build
+++ b/gfx/qcms/moz.build
@@ -12,18 +12,16 @@ EXPORTS += [
 SOURCES += [
     'chain.c',
     'iccread.c',
     'matrix.c',
     'transform.c',
     'transform_util.c',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 
 if CONFIG['GNU_CC']:
     CFLAGS += ['-Wno-missing-field-initializers']
 
 use_sse1 = False
 use_sse2 = False
 use_altivec = False

--- a/gfx/skia/generate_mozbuild.py
+++ b/gfx/skia/generate_mozbuild.py
@@ -43,18 +43,16 @@ if CONFIG['INTEL_ARCHITECTURE'] and CONF
         SOURCES += [
             'trunk/src/opts/SkBlitRow_opts_SSE4_x64_asm.S',
         ]
     else:
         SOURCES += [
             'trunk/src/opts/SkBlitRow_opts_SSE4_asm.S',
         ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 LOCAL_INCLUDES += [
     'trunk/include/config',
     'trunk/include/core',
     'trunk/include/effects',
     'trunk/include/gpu',
     'trunk/include/images',
     'trunk/include/pathops',

--- a/gfx/skia/moz.build
+++ b/gfx/skia/moz.build
@@ -875,18 +875,16 @@ if CONFIG['INTEL_ARCHITECTURE'] and CONF
         SOURCES += [
             'trunk/src/opts/SkBlitRow_opts_SSE4_x64_asm.S',
         ]
     else:
         SOURCES += [
             'trunk/src/opts/SkBlitRow_opts_SSE4_asm.S',
         ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 LOCAL_INCLUDES += [
     'trunk/include/config',
     'trunk/include/core',
     'trunk/include/effects',
     'trunk/include/gpu',
     'trunk/include/images',
     'trunk/include/pathops',

--- a/gfx/src/moz.build
+++ b/gfx/src/moz.build
@@ -66,18 +66,16 @@ UNIFIED_SOURCES += [
 
 # nsDeviceContext.cpp cannot be built in unified mode because it pulls in OS X system headers.
 SOURCES += [
     'nsDeviceContext.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 CXXFLAGS += CONFIG['MOZ_CAIRO_CFLAGS']
 CXXFLAGS += CONFIG['TK_CFLAGS']
 
 if CONFIG['MOZ_WIDGET_GTK']:
     CXXFLAGS += CONFIG['MOZ_PANGO_CFLAGS']
 

--- a/gfx/thebes/moz.build
+++ b/gfx/thebes/moz.build
@@ -250,18 +250,16 @@ UNIFIED_SOURCES += [
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     UNIFIED_SOURCES += [
         'gfxMacPlatformFontList.mm',
     ]
 
 FAIL_ON_WARNINGS = not CONFIG['_MSC_VER']
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 GENERATED_FILES = [
     'DeprecatedPremultiplyTables.h',
 ]
 

--- a/gfx/vr/moz.build
+++ b/gfx/vr/moz.build
@@ -20,14 +20,12 @@ UNIFIED_SOURCES += [
 
 CXXFLAGS += CONFIG['MOZ_CAIRO_CFLAGS']
 CXXFLAGS += CONFIG['TK_CFLAGS']
 CFLAGS += CONFIG['MOZ_CAIRO_CFLAGS']
 CFLAGS += CONFIG['TK_CFLAGS']
 
 FAIL_ON_WARNINGS = not CONFIG['_MSC_VER']
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 

--- a/intl/hyphenation/moz.build
+++ b/intl/hyphenation/moz.build
@@ -15,18 +15,16 @@ UNIFIED_SOURCES += [
 ]
 
 # These files cannot be built in unified mode because they include hnjalloc.h.
 SOURCES += [
     'hnjstdio.cpp',
     'hyphen.c',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 # Suppress warnings in third-party code.
 if CONFIG['GNU_CC']:
     CFLAGS += [
         '-Wno-sign-compare',
         '-Wno-type-limits',
     ]

--- a/intl/locale/moz.build
+++ b/intl/locale/moz.build
@@ -43,18 +43,16 @@ UNIFIED_SOURCES += [
     'nsScriptableDateFormat.cpp',
     'nsUConvPropertySearch.cpp',
 ]
 
 EXTRA_JS_MODULES += [
     'PluralForm.jsm',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/intl/uconv',
 ]
 
 RESOURCE_FILES += [
     'langGroups.properties',

--- a/intl/lwbrk/moz.build
+++ b/intl/lwbrk/moz.build
@@ -39,16 +39,14 @@ elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'co
 else:
     SOURCES += [
         'nsRuleBreaker.cpp',
     ]
     SOURCES += [
         'rulebrk.c',
     ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['MOZ_WIDGET_GTK']:
     CXXFLAGS += CONFIG['MOZ_PANGO_CFLAGS']
 
 FAIL_ON_WARNINGS = True

--- a/intl/strres/moz.build
+++ b/intl/strres/moz.build
@@ -13,13 +13,11 @@ XPIDL_SOURCES += [
 
 XPIDL_MODULE = 'intl'
 
 UNIFIED_SOURCES += [
     'nsStringBundle.cpp',
     'nsStringBundleTextOverride.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 FAIL_ON_WARNINGS = True

--- a/intl/uconv/moz.build
+++ b/intl/uconv/moz.build
@@ -152,18 +152,16 @@ UNIFIED_SOURCES += [
     'util/umap.c',
     'util/uscan.c',
 ]
 
 if CONFIG['INTEL_ARCHITECTURE']:
     SOURCES += ['nsUTF8ToUnicodeSSE2.cpp']
     SOURCES['nsUTF8ToUnicodeSSE2.cpp'].flags += CONFIG['SSE2_FLAGS']
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     'ucvcn',
     'ucvja',
     'ucvko',
     'ucvlatin',
     'ucvtw',
     'util',
 ]

--- a/js/src/moz.build
+++ b/js/src/moz.build
@@ -463,18 +463,16 @@ if CONFIG['HAVE_LINUX_PERF_EVENT_H']:
         'perf/pm_linux.cpp'
     ]
     SOURCES['perf/pm_linux.cpp'].flags += [CONFIG['LINUX_HEADERS_INCLUDES']]
 else:
     SOURCES += [
         'perf/pm_stub.cpp'
     ]
 
-MSVC_ENABLE_PGO = True
-
 HostSimplePrograms([
     'host_jskwgen',
 ])
 
 # JavaScript must be built shared, even for static builds, as it is used by
 # other modules which are always built shared. Failure to do so results in
 # the js code getting copied into xpinstall and jsd as well as mozilla-bin,
 # and then the static data cells used for locking no longer work.

--- a/js/xpconnect/loader/moz.build
+++ b/js/xpconnect/loader/moz.build
@@ -13,18 +13,16 @@ SOURCES += [
 
 EXTRA_JS_MODULES += [
     'ISO8601DateUtils.jsm',
     'XPCOMUtils.jsm',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../src',
     '../wrappers',
     '/dom/base',
 ]
 

--- a/js/xpconnect/src/moz.build
+++ b/js/xpconnect/src/moz.build
@@ -47,18 +47,16 @@ UNIFIED_SOURCES += [
 
 # XPCComponents.cpp cannot be built in unified mode because it uses plarena.h.
 SOURCES += [
     'XPCComponents.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../loader',
     '../wrappers',
     '/caps',

--- a/js/xpconnect/wrappers/moz.build
+++ b/js/xpconnect/wrappers/moz.build
@@ -25,18 +25,16 @@ SOURCES += [
 # warning C4661 for FilteringWrapper
 if CONFIG['_MSC_VER']:
     CXXFLAGS += [
         '-wd4661', # no suitable definition provided for explicit template instantiation request
     ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../../../dom/base',
     '../src',
 ]

--- a/layout/base/moz.build
+++ b/layout/base/moz.build
@@ -143,18 +143,16 @@ UNIFIED_SOURCES += [
 # nsRefreshDriver.cpp needs to be built separately because of name clashes in the OS X headers
 SOURCES += [
     'nsPresArena.cpp',
     'nsRefreshDriver.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '../forms',
     '../generic',
     '../mathml',
     '../printing',
     '../style',

--- a/layout/build/moz.build
+++ b/layout/build/moz.build
@@ -18,18 +18,16 @@ UNIFIED_SOURCES += [
 
 if CONFIG['MOZ_NFC']:
     LOCAL_INCLUDES += [
         '/dom/nfc'
     ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '../base',
     '../forms',
     '../generic',
     '../inspector',
     '../mathml',

--- a/layout/forms/moz.build
+++ b/layout/forms/moz.build
@@ -37,18 +37,16 @@ UNIFIED_SOURCES += [
     'nsProgressFrame.cpp',
     'nsRangeFrame.cpp',
     'nsSelectsAreaFrame.cpp',
     'nsTextControlFrame.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../../editor/libeditor',
     '../../editor/txmgr',
     '../base',
     '../generic',
     '../style',

--- a/layout/generic/moz.build
+++ b/layout/generic/moz.build
@@ -172,18 +172,16 @@ UNIFIED_SOURCES += [
 # nsPluginFrame.cpp needs to be built separately because of name clashes in the OS X headers.
 SOURCES += [
     'nsLineLayout.cpp',
     'nsPluginFrame.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../../dom/plugins/base',
     '../base',
     '../forms',

--- a/layout/style/moz.build
+++ b/layout/style/moz.build
@@ -173,18 +173,16 @@ SOURCES += [
 
 EXTRA_COMPONENTS += [
     'CSSUnprefixingService.js',
     'CSSUnprefixingService.manifest',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../base',
     '../generic',
     '../svg',

--- a/layout/tables/moz.build
+++ b/layout/tables/moz.build
@@ -25,18 +25,16 @@ UNIFIED_SOURCES += [
     'nsTablePainter.cpp',
     'nsTableRowFrame.cpp',
     'nsTableRowGroupFrame.cpp',
     'SpanningCellSorter.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../../intl/unicharutil/util',
     '../base',
     '../generic',
     '../style',
     '../xul',

--- a/layout/xul/moz.build
+++ b/layout/xul/moz.build
@@ -92,17 +92,15 @@ if CONFIG['MOZ_XUL']:
         'ScrollBoxObject.cpp',
     ]
 
 if CONFIG['MOZ_XUL']:
     DIRS += ['tree', 'grid']
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 LOCAL_INCLUDES += [
     '../base',
     '../generic',
     '../style',
     '/dom/base',
 ]

--- a/media/libcubeb/src/moz.build
+++ b/media/libcubeb/src/moz.build
@@ -53,18 +53,16 @@ if CONFIG['OS_TARGET'] == 'Android':
     SOURCES['cubeb_opensl.c'].flags += ['-Wno-declaration-after-statement']
     DEFINES['USE_OPENSL'] = True
     if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'gonk':
         SOURCES += [
             'cubeb_audiotrack.c',
         ]
         DEFINES['USE_AUDIOTRACK'] = True
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
     CFLAGS += [
         '-I%s/%s' % (CONFIG['ANDROID_SOURCE'], d) for d in [

--- a/media/libjpeg/moz.build
+++ b/media/libjpeg/moz.build
@@ -145,15 +145,13 @@ elif CONFIG['LIBJPEG_TURBO_X86_ASM']:
     SOURCES += [
         'simd/jsimd_i386.c',
     ]
 else: # No SIMD support?
     SOURCES += [
         'jsimd_none.c',
     ]
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'
 

--- a/media/libnestegg/src/moz.build
+++ b/media/libnestegg/src/moz.build
@@ -4,14 +4,12 @@
 # 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 += [
     'halloc.c',
     'nestegg.c',
 ]
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'

--- a/media/libogg/moz.build
+++ b/media/libogg/moz.build
@@ -14,14 +14,12 @@ EXPORTS.ogg += [
 ]
 
 UNIFIED_SOURCES += [
     'src/ogg_alloc.c',
     'src/ogg_bitwise.c',
     'src/ogg_framing.c',
 ]
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'

--- a/media/libopus/moz.build
+++ b/media/libopus/moz.build
@@ -9,18 +9,16 @@ with Files('*'):
 
 EXPORTS.opus += [
     'include/opus.h',
     'include/opus_defines.h',
     'include/opus_multistream.h',
     'include/opus_types.h',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 
 DEFINES['OPUS_BUILD'] = True
 DEFINES['OPUS_VERSION'] = '"v1.1-mozilla"'
 DEFINES['USE_ALLOCA'] = True
 
 # We only need to export symbols if we're built into libgkmedias
 # instead of libxul.

--- a/media/libpng/moz.build
+++ b/media/libpng/moz.build
@@ -35,14 +35,12 @@ if CONFIG['MOZ_PNG_ARM_NEON']:
     ]
 
     SOURCES += [
         'arm/filter_neon.S'
     ]
 
 Library('mozpng')
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'

--- a/media/libsoundtouch/src/moz.build
+++ b/media/libsoundtouch/src/moz.build
@@ -27,17 +27,16 @@ UNIFIED_SOURCES += [
 if CONFIG['INTEL_ARCHITECTURE']:
     if CONFIG['MOZ_SAMPLE_TYPE_FLOAT32']:
         SOURCES += ['sse_optimized.cpp']
         SOURCES['sse_optimized.cpp'].flags += CONFIG['SSE2_FLAGS']
     else:
         SOURCES += ['mmx_optimized.cpp']
         SOURCES['mmx_optimized.cpp'].flags += CONFIG['MMX_FLAGS']
 
-MSVC_ENABLE_PGO = True
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'
 
 # Use abort() instead of exception in SoundTouch.
 DEFINES['ST_NO_EXCEPTION_HANDLING'] = 1
 

--- a/media/libspeex_resampler/src/moz.build
+++ b/media/libspeex_resampler/src/moz.build
@@ -10,18 +10,16 @@ EXPORTS.speex += [
     'speex_resampler.h',
 ]
 
 SOURCES += [
     'resample.c',
     'simd_detect.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 
 # We don't compile the full speex codec, only the resampler.
 DEFINES['OUTSIDE_SPEEX'] = True
 
 # Visibility is handled through VISIBILITY_FLAGS and
 # layout/media/symbols.def.in.
 DEFINES['EXPORT'] = ''

--- a/media/libtheora/moz.build
+++ b/media/libtheora/moz.build
@@ -8,18 +8,16 @@ with Files('*'):
     BUG_COMPONENT = ('Core', 'Video/Audio')
 
 EXPORTS.theora += [
     'include/theora/codec.h',
     'include/theora/theoradec.h',
     'include/theora/theoraenc.h',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 # The encoder is currently not included.
 DEFINES['THEORA_DISABLE_ENCODE'] = True
 

--- a/media/libvorbis/moz.build
+++ b/media/libvorbis/moz.build
@@ -43,18 +43,16 @@ SOURCES += [
 LOCAL_INCLUDES += ['lib']
 
 if CONFIG['OS_ARCH'] == 'AIX':
     DEFINES['alloca'] = '__alloca'
 
 if CONFIG['OS_ARCH'] == 'SunOS':
     DEFINES['HAVE_ALLOCA_H'] = True
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'
 
 # Suppress warnings in third-party code.
 if CONFIG['GNU_CC']:
     CFLAGS += ['-Wno-uninitialized']

--- a/media/libvpx/moz.build
+++ b/media/libvpx/moz.build
@@ -68,18 +68,16 @@ if CONFIG['VPX_ARM_ASM']:
 
 # boolhuff_armv5te.asm defines the same functions as boolhuff.c instead of
 # using RTCD, so we have to make sure we only add one of the two.
 if 'vp8/encoder/arm/armv5te/boolhuff_armv5te.asm' not in arm_asm_files:
     SOURCES += [
         'vp8/encoder/boolhuff.c',
     ]
 
-MSVC_ENABLE_PGO = True
-
 if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
     NO_VISIBILITY_FLAGS = True
 
 FINAL_LIBRARY = 'gkmedias'
 
 DEFINES['HAVE_CONFIG_H'] = 'vpx_config.h'
 
 if CONFIG['OS_TARGET'] == 'Android':

--- a/modules/libjar/moz.build
+++ b/modules/libjar/moz.build
@@ -39,13 +39,11 @@ SOURCES += [
     'nsJARChannel.cpp',
     'nsJARFactory.cpp',
     'nsJARInputStream.cpp',
     'nsZipArchive.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

--- a/modules/libjar/zipwriter/moz.build
+++ b/modules/libjar/zipwriter/moz.build
@@ -16,13 +16,11 @@ UNIFIED_SOURCES += [
     'nsDeflateConverter.cpp',
     'nsZipDataStream.cpp',
     'nsZipHeader.cpp',
     'nsZipWriter.cpp',
     'StreamFunctions.cpp',
     'ZipWriterModule.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 FAIL_ON_WARNINGS = True

--- a/modules/libpref/moz.build
+++ b/modules/libpref/moz.build
@@ -31,18 +31,16 @@ UNIFIED_SOURCES += [
     'prefread.cpp',
 ]
 
 # prefapi.cpp cannot be built in unified mode because it uses plarena.h
 SOURCES += [
     'prefapi.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 DEFINES['OS_ARCH'] = CONFIG['OS_ARCH']
 DEFINES['MOZ_WIDGET_TOOLKIT'] = CONFIG['MOZ_WIDGET_TOOLKIT']
 
 FAIL_ON_WARNINGS = True

--- a/netwerk/base/moz.build
+++ b/netwerk/base/moz.build
@@ -268,18 +268,16 @@ EXTRA_COMPONENTS += [
 ]
 
 EXTRA_JS_MODULES += [
     'NetUtil.jsm',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/dom/base',
     '/netwerk/protocol/http'
 ]

--- a/netwerk/build/moz.build
+++ b/netwerk/build/moz.build
@@ -9,18 +9,16 @@ EXPORTS += [
 ]
 
 SOURCES += [
     'nsNetModule.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/netwerk/base',
     '/netwerk/cache',
     '/netwerk/dns',

--- a/netwerk/cache/moz.build
+++ b/netwerk/cache/moz.build
@@ -38,15 +38,13 @@ UNIFIED_SOURCES += [
     'nsDiskCacheEntry.cpp',
     'nsDiskCacheMap.cpp',
     'nsDiskCacheStreams.cpp',
     'nsMemoryCacheDevice.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/netwerk/base',
 ]

--- a/netwerk/cache2/moz.build
+++ b/netwerk/cache2/moz.build
@@ -49,11 +49,9 @@ SOURCES += [
 
 LOCAL_INCLUDES += [
     '/netwerk/base',
     '/netwerk/cache',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'

--- a/netwerk/cookie/moz.build
+++ b/netwerk/cookie/moz.build
@@ -12,18 +12,16 @@ XPIDL_SOURCES += [
     'nsICookieManager2.idl',
     'nsICookiePermission.idl',
     'nsICookieService.idl',
 ]
 
 XPIDL_MODULE = 'necko_cookie'
 
 if CONFIG['NECKO_COOKIES']:
-    MSVC_ENABLE_PGO = True
-
     EXPORTS.mozilla.net = [
         'CookieServiceChild.h',
         'CookieServiceParent.h',
     ]
     UNIFIED_SOURCES += [
         'CookieServiceChild.cpp',
         'CookieServiceParent.cpp',
         'nsCookie.cpp',

--- a/netwerk/dns/moz.build
+++ b/netwerk/dns/moz.build
@@ -45,18 +45,16 @@ UNIFIED_SOURCES += [
 
 IPDL_SOURCES = [
     'PDNSRequest.ipdl',
     'PDNSRequestParams.ipdlh',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 GENERATED_FILES = [
     'etld_data.inc',
 ]
 etld_data = GENERATED_FILES['etld_data.inc']

--- a/netwerk/mime/moz.build
+++ b/netwerk/mime/moz.build
@@ -17,11 +17,9 @@ EXPORTS += [
 ]
 
 SOURCES += [
     'nsMIMEHeaderParamImpl.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'

--- a/netwerk/protocol/file/moz.build
+++ b/netwerk/protocol/file/moz.build
@@ -17,15 +17,13 @@ XPIDL_MODULE = 'necko_file'
 
 UNIFIED_SOURCES += [
     'nsFileChannel.cpp',
     'nsFileProtocolHandler.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/netwerk/base',
 ]

--- a/netwerk/protocol/ftp/moz.build
+++ b/netwerk/protocol/ftp/moz.build
@@ -29,17 +29,15 @@ UNIFIED_SOURCES += [
 ]
 
 IPDL_SOURCES += [
     'PFTPChannel.ipdl',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/netwerk/base',
 ]

--- a/netwerk/protocol/http/moz.build
+++ b/netwerk/protocol/http/moz.build
@@ -96,18 +96,16 @@ IPDL_SOURCES += [
 
 EXTRA_JS_MODULES += [
     'UserAgentOverrides.jsm',
     'UserAgentUpdates.jsm',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/dom/base',
     '/netwerk/base',
 ]

--- a/netwerk/protocol/res/moz.build
+++ b/netwerk/protocol/res/moz.build
@@ -11,17 +11,15 @@ XPIDL_SOURCES += [
 XPIDL_MODULE = 'necko_res'
 
 SOURCES += [
     'nsResProtocolHandler.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/netwerk/base',
 ]

--- a/netwerk/protocol/rtsp/moz.build
+++ b/netwerk/protocol/rtsp/moz.build
@@ -39,18 +39,16 @@ SOURCES += [
     'rtsp/ARTPWriter.cpp',
     'rtsp/ARTSPConnection.cpp',
     'rtsp/ASessionDescription.cpp',
     'rtsp/RTSPSource.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 # Suppress some GCC warnings being treated as errors:
 #  - about attributes on forward declarations for types that are already
 #    defined, which complains about an important MOZ_EXPORT for android::AString
 if CONFIG['GNU_CC']:
   CXXFLAGS += ['-Wno-error=attributes']
 

--- a/netwerk/protocol/websocket/moz.build
+++ b/netwerk/protocol/websocket/moz.build
@@ -26,18 +26,16 @@ UNIFIED_SOURCES += [
 ]
 
 IPDL_SOURCES += [
     'PWebSocket.ipdl',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/dom/base',
     '/netwerk/base',
 ]

--- a/netwerk/streamconv/converters/moz.build
+++ b/netwerk/streamconv/converters/moz.build
@@ -23,15 +23,13 @@ if 'ftp' in CONFIG['NECKO_PROTOCOLS']:
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'cocoa':
     UNIFIED_SOURCES += [
         'nsBinHexDecoder.cpp',
     ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/netwerk/base',
 ]

--- a/netwerk/streamconv/moz.build
+++ b/netwerk/streamconv/moz.build
@@ -19,11 +19,9 @@ XPIDL_SOURCES += [
 SOURCES += [
     'nsStreamConverterService.cpp',
 ]
 
 XPIDL_MODULE = 'necko_strconv'
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'

--- a/parser/expat/lib/moz.build
+++ b/parser/expat/lib/moz.build
@@ -10,13 +10,11 @@ EXPORTS += [
 ]
 
 SOURCES += [
     'xmlparse.c',
     'xmlrole.c',
     'xmltok.c',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'gkmedias'
 
 DEFINES['HAVE_EXPAT_CONFIG_H'] = True

--- a/parser/html/moz.build
+++ b/parser/html/moz.build
@@ -85,18 +85,16 @@ UNIFIED_SOURCES += [
     'nsHtml5TreeOperation.cpp',
     'nsHtml5TreeOpExecutor.cpp',
     'nsHtml5TreeOpStage.cpp',
     'nsHtml5UTF16Buffer.cpp',
     'nsHtml5ViewSourceUtils.cpp',
     'nsParserUtils.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 # DEFINES['ENABLE_VOID_MENUITEM'] = True
 
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 

--- a/parser/xml/moz.build
+++ b/parser/xml/moz.build
@@ -28,13 +28,11 @@ EXPORTS += [
 ]
 
 SOURCES += [
     'nsSAXAttributes.cpp',
     'nsSAXLocator.cpp',
     'nsSAXXMLReader.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 FAIL_ON_WARNINGS = True

--- a/python/mozbuild/mozbuild/backend/recursivemake.py
+++ b/python/mozbuild/mozbuild/backend/recursivemake.py
@@ -92,17 +92,16 @@ MOZBUILD_VARIABLES = [
     'IS_COMPONENT',
     'JAR_MANIFEST',
     'JAVA_JAR_TARGETS',
     'LD_VERSION_SCRIPT',
     'LIBRARY_NAME',
     'LIBS',
     'MAKE_FRAMEWORK',
     'MODULE',
-    'MSVC_ENABLE_PGO',
     'NO_DIST_INSTALL',
     'NO_JS_MANIFEST',
     'OS_LIBS',
     'PARALLEL_DIRS',
     'PREF_JS_EXPORTS',
     'PROGRAM',
     'PYTHON_UNIT_TESTS',
     'RESOURCE_FILES',

--- a/python/mozbuild/mozbuild/frontend/context.py
+++ b/python/mozbuild/mozbuild/frontend/context.py
@@ -905,20 +905,16 @@ VARIABLES = {
     'HOST_OS_LIBS': (List, list,
         """List of system libraries for host programs and libraries.
         """, None),
 
     'LOCAL_INCLUDES': (StrictOrderingOnAppendList, list,
         """Additional directories to be searched for include files by the compiler.
         """, None),
 
-    'MSVC_ENABLE_PGO': (bool, bool,
-        """Whether profile-guided optimization is enabled for MSVC in this directory.
-        """, None),
-
     'NO_PGO': (bool, bool,
         """Whether profile-guided optimization is disable in this directory.
         """, None),
 
     'NO_VISIBILITY_FLAGS': (bool, bool,
         """Build sources listed in this file without VISIBILITY_FLAGS.
         """, None),
 

--- a/python/mozbuild/mozbuild/frontend/emitter.py
+++ b/python/mozbuild/mozbuild/frontend/emitter.py
@@ -548,17 +548,16 @@ class TreeMetadataEmitter(LoggingMixin):
             'EXTRA_ASSEMBLER_FLAGS',
             'EXTRA_COMPILE_FLAGS',
             'EXTRA_COMPONENTS',
             'EXTRA_DSO_LDOPTS',
             'EXTRA_PP_COMPONENTS',
             'FAIL_ON_WARNINGS',
             'USE_STATIC_LIBS',
             'IS_GYP_DIR',
-            'MSVC_ENABLE_PGO',
             'NO_DIST_INSTALL',
             'PYTHON_UNIT_TESTS',
             'RCFILE',
             'RESFILE',
             'RCINCLUDE',
             'DEFFILE',
             'WIN32_EXE_LDFLAGS',
             'LD_VERSION_SCRIPT',

--- a/python/mozbuild/mozbuild/test/backend/data/variable_passthru/moz.build
+++ b/python/mozbuild/mozbuild/test/backend/data/variable_passthru/moz.build
@@ -1,17 +1,16 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # Any copyright is dedicated to the Public Domain.
 # http://creativecommons.org/publicdomain/zero/1.0/
 
 EXTRA_COMPONENTS = ['bar.js', 'dummy.manifest', 'foo.js']
 EXTRA_PP_COMPONENTS = ['bar.pp.js', 'foo.pp.js']
 
 FAIL_ON_WARNINGS = True
-MSVC_ENABLE_PGO = True
 NO_VISIBILITY_FLAGS = True
 
 DELAYLOAD_DLLS = ['foo.dll', 'bar.dll']
 
 RCFILE = 'foo.rc'
 RESFILE = 'bar.res'
 RCINCLUDE = 'bar.rc'
 DEFFILE = 'baz.def'

--- a/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
+++ b/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
@@ -270,19 +270,16 @@ class TestRecursiveMakeBackend(BackendTe
             ],
             'EXTRA_PP_COMPONENTS': [
                 'EXTRA_PP_COMPONENTS += bar.pp.js',
                 'EXTRA_PP_COMPONENTS += foo.pp.js',
             ],
             'FAIL_ON_WARNINGS': [
                 'FAIL_ON_WARNINGS := 1',
             ],
-            'MSVC_ENABLE_PGO': [
-                'MSVC_ENABLE_PGO := 1',
-            ],
             'VISIBILITY_FLAGS': [
                 'VISIBILITY_FLAGS :=',
             ],
             'RCFILE': [
                 'RCFILE := foo.rc',
             ],
             'RESFILE': [
                 'RESFILE := bar.res',

--- a/python/mozbuild/mozbuild/test/frontend/data/variable-passthru/moz.build
+++ b/python/mozbuild/mozbuild/test/frontend/data/variable-passthru/moz.build
@@ -1,18 +1,16 @@
 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
 # Any copyright is dedicated to the Public Domain.
 # http://creativecommons.org/publicdomain/zero/1.0/
 
 EXTRA_COMPONENTS = ['dummy.manifest', 'fans.js', 'tans.js']
 EXTRA_PP_COMPONENTS=['fans.pp.js', 'tans.pp.js']
 
 FAIL_ON_WARNINGS = True
-MSVC_ENABLE_PGO = True
-
 NO_DIST_INSTALL = True
 
 NO_VISIBILITY_FLAGS = True
 
 DELAYLOAD_DLLS = ['foo.dll', 'bar.dll']
 
 RCFILE = 'foo.rc'
 RESFILE = 'bar.res'

--- a/python/mozbuild/mozbuild/test/frontend/test_emitter.py
+++ b/python/mozbuild/mozbuild/test/frontend/test_emitter.py
@@ -158,17 +158,16 @@ class TestEmitterBasic(unittest.TestCase
         self.assertEqual(len(objs), 1)
         self.assertIsInstance(objs[0], VariablePassthru)
 
         wanted = {
             'DISABLE_STL_WRAPPING': True,
             'EXTRA_COMPONENTS': ['dummy.manifest', 'fans.js', 'tans.js'],
             'EXTRA_PP_COMPONENTS': ['fans.pp.js', 'tans.pp.js'],
             'FAIL_ON_WARNINGS': True,
-            'MSVC_ENABLE_PGO': True,
             'NO_DIST_INSTALL': True,
             'VISIBILITY_FLAGS': '',
             'RCFILE': 'foo.rc',
             'RESFILE': 'bar.res',
             'RCINCLUDE': 'bar.rc',
             'DEFFILE': 'baz.def',
             'USE_STATIC_LIBS': True,
             'MOZBUILD_CFLAGS': ['-fno-exceptions', '-w'],

--- a/security/manager/boot/src/moz.build
+++ b/security/manager/boot/src/moz.build
@@ -25,11 +25,9 @@ LOCAL_INCLUDES += [
 ]
 
 GENERATED_INCLUDES += [
     '/dist/public/nss',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'

--- a/toolkit/components/places/moz.build
+++ b/toolkit/components/places/moz.build
@@ -9,18 +9,16 @@ if CONFIG['MOZ_PLACES']:
 
 XPIDL_SOURCES += [
     'nsINavHistoryService.idl',
 ]
 
 XPIDL_MODULE = 'places'
 
 if CONFIG['MOZ_PLACES']:
-    MSVC_ENABLE_PGO = True
-
     XPIDL_SOURCES += [
         'mozIAsyncFavicons.idl',
         'mozIAsyncHistory.idl',
         'mozIAsyncLivemarks.idl',
         'mozIColorAnalyzer.idl',
         'mozIPlacesAutoComplete.idl',
         'nsIAnnotationService.idl',
         'nsIBrowserHistory.idl',

--- a/toolkit/components/telemetry/moz.build
+++ b/toolkit/components/telemetry/moz.build
@@ -41,18 +41,16 @@ EXTRA_JS_MODULES += [
 EXTRA_PP_JS_MODULES += [
     'TelemetryEnvironment.jsm',
     'TelemetryPing.jsm',
     'TelemetrySession.jsm',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 GENERATED_FILES = [
     'TelemetryHistogramData.inc',
 ]
 

--- a/toolkit/components/url-classifier/moz.build
+++ b/toolkit/components/url-classifier/moz.build
@@ -57,18 +57,16 @@ EXTRA_JS_MODULES += [
 EXPORTS += [
     'Entries.h',
     'LookupCache.h',
     'nsUrlClassifierPrefixSet.h',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../build',
     '/ipc/chromium/src',
 ]
 
 CXXFLAGS += CONFIG['SQLITE_CFLAGS']

--- a/toolkit/crashreporter/google-breakpad/src/common/moz.build
+++ b/toolkit/crashreporter/google-breakpad/src/common/moz.build
@@ -73,18 +73,16 @@ if CONFIG['OS_ARCH'] == 'Darwin':
 if CONFIG['OS_TARGET'] == 'Android':
     # We don't support unifying assembly files.
     SOURCES += [
         'android/breakpad_getcontext.S',
     ]
 
 Library('breakpad_common_s')
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
     DEFINES['ELFSIZE'] = 32
 
 if CONFIG['OS_TARGET'] == 'Android':
     DEFINES['NO_STABS_SUPPORT'] = True
 

--- a/toolkit/crashreporter/moz.build
+++ b/toolkit/crashreporter/moz.build
@@ -73,18 +73,16 @@ if CONFIG['OS_ARCH'] == 'Darwin':
     ]
 
 EXTRA_JS_MODULES += [
     'CrashReports.jsm',
     'CrashSubmit.jsm',
     'KeyValueParser.jsm',
 ]
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['OS_TARGET'] == 'Android':
     DEFINES['ANDROID_PACKAGE_NAME'] = '"%s"' % CONFIG['ANDROID_PACKAGE_NAME']
     # NDK5 workarounds
     DEFINES['_STLP_CONST_CONSTRUCTOR_BUG'] = True

--- a/toolkit/library/moz.build
+++ b/toolkit/library/moz.build
@@ -1,18 +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/.
 
 @template
 def Libxul(name):
-    MSVC_ENABLE_PGO = True
-
     if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
         # This is going to be a framework named "XUL", not an ordinary library named
         # "libxul.dylib"
         GeckoFramework(name, linkage=None)
         SHARED_LIBRARY_NAME = 'XUL'
     else:
         GeckoSharedLibrary(name, linkage=None)
         SHARED_LIBRARY_NAME = 'xul'
@@ -58,18 +56,16 @@ SDK_LIBRARY = True
 FORCE_STATIC_LIB = True
 
 STATIC_LIBRARY_NAME = 'xul_s'
 
 SOURCES += [
     'StaticXULComponentsStart.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 # This, combined with the fact the file is first, makes the start pointer
 # it contains first in Windows PGO builds.
 SOURCES['StaticXULComponentsStart.cpp'].no_pgo = True
 
 # Don't let LTO reorder StaticXULComponentsStart.o.
 if '-flto' in CONFIG['OS_CXXFLAGS']:
     SOURCES['StaticXULComponentsStart.cpp'].flags += ['-fno-lto']
 

--- a/toolkit/xre/moz.build
+++ b/toolkit/xre/moz.build
@@ -100,18 +100,16 @@ if CONFIG['MOZ_INSTRUMENT_EVENT_LOOP']:
     ]
 
 if CONFIG['MOZ_UPDATER']:
     if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'android':
         UNIFIED_SOURCES += [
             'nsUpdateDriver.cpp',
         ]
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['MOZ_GL_DEFAULT_PROVIDER'] == 'GLX':
     DEFINES['USE_GLX_TEST'] = True
 
 for var in ('MOZ_APP_NAME', 'MOZ_APP_BASENAME', 'MOZ_APP_VERSION', 'OS_TARGET',

--- a/uriloader/base/moz.build
+++ b/uriloader/base/moz.build
@@ -25,11 +25,9 @@ EXPORTS += [
 
 UNIFIED_SOURCES += [
     'nsDocLoader.cpp',
     'nsURILoader.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'

--- a/view/moz.build
+++ b/view/moz.build
@@ -12,13 +12,11 @@ EXPORTS += [
 # nsViewManager.cpp cannot be built in unified mode because it uses PL_ARENA_CONST_ALIGN_MASK.
 SOURCES += [
     'nsView.cpp',
     'nsViewManager.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 CXXFLAGS += CONFIG['MOZ_CAIRO_CFLAGS']

--- a/widget/moz.build
+++ b/widget/moz.build
@@ -209,18 +209,16 @@ if toolkit in ('qt', 'gtk2', 'gtk3', 'wi
         'nsNativeTheme.cpp',
     ]
 
 if not CONFIG['MOZ_B2G']:
     DEFINES['MOZ_CROSS_PROCESS_IME'] = True
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 LOCAL_INCLUDES += [
     '/dom/base',
     '/dom/ipc',
     '/layout/base',
     '/layout/forms',
     '/layout/generic',

--- a/widget/windows/moz.build
+++ b/widget/windows/moz.build
@@ -80,18 +80,16 @@ if CONFIG['NS_PRINTING']:
 
 if CONFIG['NS_ENABLE_TSF']:
     SOURCES += [
         'nsTextStore.cpp',
     ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '/layout/generic',
     '/layout/xul',
     '/toolkit/xre',

--- a/xpcom/base/moz.build
+++ b/xpcom/base/moz.build
@@ -146,18 +146,16 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'coco
     SOURCES += [
         'nsMacUtilsImpl.cpp',
     ]
 elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
     SOURCES += [
         'nsCrashOnException.cpp',
     ]
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 LOCAL_INCLUDES += [
     '../build',
     '/xpcom/ds',
 ]

--- a/xpcom/build/moz.build
+++ b/xpcom/build/moz.build
@@ -65,18 +65,16 @@ if CONFIG['OS_ARCH'] != 'WINNT':
 # use plarena.h.
 SOURCES += [
     'FileLocation.cpp',
     'Omnijar.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 DEFINES['_IMPL_NS_STRINGAPI'] = True
 DEFINES['OMNIJAR_NAME'] = CONFIG['OMNIJAR_NAME']
 
 GENERATED_INCLUDES += ['..']

--- a/xpcom/components/moz.build
+++ b/xpcom/components/moz.build
@@ -36,18 +36,16 @@ SOURCES += [
 
 UNIFIED_SOURCES += [
     'ManifestParser.cpp',
     'nsNativeModuleLoader.cpp',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 GENERATED_INCLUDES += ['..']
 LOCAL_INCLUDES += [
     '../base',
     '../build',
     '../ds',
     '../reflect/xptinfo',

--- a/xpcom/ds/moz.build
+++ b/xpcom/ds/moz.build
@@ -108,15 +108,13 @@ elif CONFIG['COMPILE_ENVIRONMENT']:
 
 EXTRA_COMPONENTS += [
     'nsINIProcessor.js',
     'nsINIProcessor.manifest',
 ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '../io',
 ]
 
 FINAL_LIBRARY = 'xul'

--- a/xpcom/io/moz.build
+++ b/xpcom/io/moz.build
@@ -120,18 +120,16 @@ UNIFIED_SOURCES += [
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     SOURCES += [
         'CocoaFileUtils.mm',
     ]
 
 FAIL_ON_WARNINGS = True
 
-MSVC_ENABLE_PGO = True
-
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'
 
 if CONFIG['OS_ARCH'] == 'Linux' and 'lib64' in CONFIG['libdir']:
     DEFINES['HAVE_USR_LIB64_DIR'] = True
 
 GENERATED_INCLUDES += ['..']

--- a/xpcom/reflect/xptcall/moz.build
+++ b/xpcom/reflect/xptcall/moz.build
@@ -11,17 +11,15 @@ SOURCES += [
 ]
 
 EXPORTS += [
     'xptcall.h',
     'xptcstubsdecl.inc',
     'xptcstubsdef.inc',
 ]
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '/xpcom/reflect/xptinfo',
 ]
 
 FINAL_LIBRARY = 'xul'
 
 FAIL_ON_WARNINGS = True

--- a/xpcom/reflect/xptinfo/moz.build
+++ b/xpcom/reflect/xptinfo/moz.build
@@ -26,13 +26,11 @@ EXPORTS += [
 EXPORTS.mozilla += [
     'XPTInterfaceInfoManager.h',
 ]
 
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 FAIL_ON_WARNINGS = True

--- a/xpcom/string/moz.build
+++ b/xpcom/string/moz.build
@@ -51,13 +51,11 @@ UNIFIED_SOURCES += [
 ]
 
 # Are we targeting x86 or x86-64?  If so, compile the SSE2 functions for
 # nsUTF8Utils.cpp.
 if CONFIG['INTEL_ARCHITECTURE']:
     SOURCES += ['nsUTF8UtilsSSE2.cpp']
     SOURCES['nsUTF8UtilsSSE2.cpp'].flags += CONFIG['SSE2_FLAGS']
 
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'
 
 FAIL_ON_WARNINGS = True

--- a/xpcom/threads/moz.build
+++ b/xpcom/threads/moz.build
@@ -47,18 +47,16 @@ UNIFIED_SOURCES += [
     'nsThread.cpp',
     'nsThreadManager.cpp',
     'nsThreadPool.cpp',
     'nsTimerImpl.cpp',
     'ThreadStackHelper.cpp',
     'TimerThread.cpp',
 ]
 
-MSVC_ENABLE_PGO = True
-
 LOCAL_INCLUDES += [
     '../build',
     '/caps',
     '/toolkit/crashreporter/google-breakpad/src',
     '/tools/profiler',
 ]
 
 # BHR disabled for Release builds because of bug 965392.

--- a/xpfe/appshell/moz.build
+++ b/xpfe/appshell/moz.build
@@ -32,11 +32,9 @@ UNIFIED_SOURCES += [
     'nsXULWindow.cpp',
 ]
 
 LOCAL_INCLUDES += [
     '/dom/base',
 ]
 
 FAIL_ON_WARNINGS = True
-MSVC_ENABLE_PGO = True
-
 FINAL_LIBRARY = 'xul'