--- a/dom/animation/test/mochitest.ini
+++ b/dom/animation/test/mochitest.ini
@@ -42,17 +42,16 @@ skip-if = (toolkit == 'android' && debug
 [mozilla/test_distance_of_filter.html]
 [mozilla/test_distance_of_path_function.html]
 [mozilla/test_distance_of_transform.html]
 [mozilla/test_document_timeline_origin_time_range.html]
 [mozilla/test_hide_and_show.html]
 [mozilla/test_moz_prefixed_properties.html]
 [mozilla/test_pending_animation_tracker.html]
 [mozilla/test_restyles.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [mozilla/test_restyling_xhr_doc.html]
 [mozilla/test_set_easing.html]
 [mozilla/test_style_after_finished_on_compositor.html]
 [mozilla/test_transform_limits.html]
 [mozilla/test_transition_finish_on_compositor.html]
 skip-if = toolkit == 'android'
 [mozilla/test_underlying_discrete_value.html]
 [mozilla/test_event_listener_leaks.html]

--- a/dom/base/test/mochitest.ini
+++ b/dom/base/test/mochitest.ini
@@ -641,17 +641,16 @@ skip-if = verify
 [test_document.all_unqualified.html]
 [test_document_constructor.html]
 [test_document_importNode_document.html]
 [test_custom_element.html]
 [test_domparser_null_char.html]
 [test_domparsing.html]
 [test_domrequest.html]
 [test_domwindowutils.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_element.matches.html]
 [test_element_closest.html]
 [test_elementTraversal.html]
 [test_encodeToStringWithMaxLength.html]
 [test_encodeToStringWithRequiresReinitAfterOutput.html]
 [test_error.html]
 [test_EventSource_redirects.html]
 [test_eventsource_event_listener_leaks.html]

--- a/dom/html/test/forms/mochitest.ini
+++ b/dom/html/test/forms/mochitest.ini
@@ -113,13 +113,13 @@ skip-if = android_version == '18' || os 
 [test_textarea_attributes_reflection.html]
 [test_validation.html]
 [test_valueAsDate_pref.html]
 [test_valueasdate_attribute.html]
 [test_valueasnumber_attribute.html]
 [test_validation_not_in_doc.html]
 [test_reportValidation_preventDefault.html]
 [test_bug1495363.html]
-skip-if = (toolkit == 'android' && !is_fennec) || (webrender && os == "linux") # Bugs 1525959, 1520674
+skip-if = (webrender && os == "linux") # Bug 1520674
 support-files =
   file_bug1495363.html
   file_bug1495363.sjs
   !/dom/filesystem/tests/script_fileList.js

--- a/dom/html/test/mochitest.ini
+++ b/dom/html/test/mochitest.ini
@@ -254,17 +254,16 @@ skip-if = toolkit == 'android' #TIMED_OU
 [test_bug401160.xhtml]
 [test_bug405242.html]
 [test_bug406596.html]
 [test_bug417760.html]
 [test_bug421640.html]
 [test_bug424698.html]
 [test_bug428135.xhtml]
 [test_bug430351.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_bug441930.html]
 [test_bug442801.html]
 [test_bug448166.html]
 [test_bug456229.html]
 [test_bug458037.xhtml]
 [test_bug460568.html]
 [test_bug481335.xhtml]
 skip-if = toolkit == 'android' #TIMED_OUT
@@ -385,17 +384,16 @@ support-files =
 [test_bug674558.html]
 [test_bug674927.html]
 [test_bug677463.html]
 [test_bug677658.html]
 [test_bug682886.html]
 [test_bug691.html]
 [test_bug694.html]
 [test_bug694503.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_bug696.html]
 [test_bug717819.html]
 [test_bug742030.html]
 [test_bug742549.html]
 [test_bug745685.html]
 [test_bug763626.html]
 [test_bug780993.html]
 [test_bug787134.html]

--- a/dom/ipc/tests/mochitest.ini
+++ b/dom/ipc/tests/mochitest.ini
@@ -12,18 +12,18 @@ skip-if = e10s
 # This test is only supposed to run in the main process
 skip-if = e10s || toolkit == 'android'
 [test_cpow_cookies.html]
 [test_child_docshell.html]
 skip-if = toolkit == 'cocoa' # cocoa: disabled due to hangs, see changeset 6852e7c47edf
 [test_CrashService_crash.html]
 skip-if = !(crashreporter && !e10s && (toolkit == 'gtk3' || toolkit == 'cocoa' || toolkit == 'windows'))
 [test_temporaryfile_stream.html]
-skip-if = !e10s || toolkit == 'android' # Bug 1525959
+skip-if = !e10s
 support-files =
   blob_verify.sjs
   !/dom/canvas/test/captureStream_common.js
 [test_Preallocated.html]
-skip-if = !e10s || toolkit == 'android' # Bug 1525959
+skip-if = !e10s
 [test_force_oop_iframe.html]
 skip-if = !e10s || webrender # oop-iframes trigger a debug assertion in webrender picture caching
 support-files =
   file_dummy.html

--- a/dom/performance/tests/mochitest.ini
+++ b/dom/performance/tests/mochitest.ini
@@ -14,15 +14,13 @@ support-files =
 [test_performance_observer.html]
 [test_performance_user_timing.html]
 [test_performance_navigation_timing.html]
 [test_worker_user_timing.html]
 [test_worker_observer.html]
 [test_sharedWorker_performance_user_timing.html]
 [test_worker_performance_now.html]
 [test_timeOrigin.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_worker_performance_entries.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_performance_timing_json.html]
 [test_performance_server_timing.html]
 scheme = https
 [test_performance_server_timing_plain_http.html]

--- a/dom/serviceworkers/test/mochitest.ini
+++ b/dom/serviceworkers/test/mochitest.ini
@@ -278,17 +278,17 @@ tags = mcb
 [test_notification_get.html]
 [test_notificationclick.html]
 [test_notificationclick_focus.html]
 [test_notificationclick-otherwindow.html]
 [test_notificationclose.html]
 [test_onmessageerror.html]
 [test_opaque_intercept.html]
 [test_openWindow.html]
-skip-if = toolkit == 'android' && !is_fennec
+skip-if = toolkit == 'android' && !isFennec
 tags = openwindow
 [test_origin_after_redirect.html]
 [test_origin_after_redirect_cached.html]
 [test_origin_after_redirect_to_https.html]
 [test_origin_after_redirect_to_https_cached.html]
 [test_post_message.html]
 [test_post_message_advanced.html]
 [test_post_message_source.html]

--- a/dom/tests/mochitest/bugs/mochitest.ini
+++ b/dom/tests/mochitest/bugs/mochitest.ini
@@ -71,17 +71,16 @@ skip-if = toolkit == 'android' #TIMED_OU
 tags = openwindow
 [test_bug427744.html]
 skip-if = toolkit == 'android'
 [test_bug42976.html]
 [test_bug430276.html]
 [test_bug440572.html]
 [test_bug456151.html]
 [test_bug458091.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_bug459848.html]
 [test_bug465263.html]
 [test_bug484775.html]
 [test_bug492925.html]
 [test_bug49312.html]
 [test_bug495219.html]
 [test_bug529328.html]
 [test_bug531176.html]

--- a/editor/libeditor/tests/mochitest.ini
+++ b/editor/libeditor/tests/mochitest.ini
@@ -177,17 +177,16 @@ subsuite = clipboard
 subsuite = clipboard
 [test_bug795418-4.html]
 subsuite = clipboard
 [test_bug795418-5.html]
 subsuite = clipboard
 [test_bug795418-6.html]
 subsuite = clipboard
 [test_bug795785.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_bug796839.html]
 [test_bug830600.html]
 subsuite = clipboard
 skip-if = toolkit == 'android' && e10s
 [test_bug832025.html]
 [test_bug850043.html]
 [test_bug857487.html]
 [test_bug858918.html]
@@ -260,17 +259,17 @@ skip-if = toolkit == 'android' # bug 131
 [test_bug1406726.html]
 [test_bug1409520.html]
 [test_bug1425997.html]
 [test_bug1497480.html]
 skip-if = toolkit == 'android'
 
 [test_abs_positioner_appearance.html]
 [test_abs_positioner_positioning_elements.html]
-skip-if = os == 'android' # Bug 1525959
+skip-if = android_version == '18' # bug 1147989
 [test_CF_HTML_clipboard.html]
 subsuite = clipboard
 [test_composition_event_created_in_chrome.html]
 [test_contenteditable_focus.html]
 [test_documentCharacterSet.html]
 [test_dom_input_event_on_htmleditor.html]
 [test_dom_input_event_on_texteditor.html]
 [test_dragdrop.html]
@@ -318,12 +317,11 @@ skip-if = toolkit == 'android' || (verif
 skip-if = toolkit == 'android'
 [test_undo_after_spellchecker_replaces_word.html]
 skip-if = toolkit == 'android'
 [test_undo_redo_stack_after_setting_value.html]
 [test_backspace_vs.html]
 [test_css_chrome_load_access.html]
 skip-if = toolkit == 'android' # chrome urls not available due to packaging
 [test_selection_move_commands.html]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_pasteImgTextarea.html]
 skip-if = toolkit == 'android' # bug 1299578
 [test_execCommandPaste_noTarget.html]

--- a/gfx/layers/apz/test/mochitest/mochitest.ini
+++ b/gfx/layers/apz/test/mochitest/mochitest.ini
@@ -24,17 +24,17 @@
   skip-if = (toolkit == 'android') # mouse events not supported on mobile
 [test_group_pointerevents.html]
   skip-if = os == 'win' && os_version == '10.0' # Bug 1404836
 [test_group_touchevents.html]
   skip-if = (verify && debug && (os == 'win'))
 [test_group_touchevents-2.html]
   skip-if = (verify && debug && (os == 'win'))
 [test_group_touchevents-3.html]
-  skip-if = (verify && debug && (os == 'win')) || (toolkit == 'android' && !is_fennec) # Bug 1525959
+  skip-if = (verify && debug && (os == 'win'))
 [test_group_touchevents-4.html]
   skip-if = (verify && debug && (os == 'win'))
 [test_group_wheelevents.html]
   skip-if = (toolkit == 'android') # wheel events not supported on mobile
 [test_group_zoom.html]
   skip-if = (os == 'win') || webrender # zooming is not supported yet on WebRender; see bug 1495580 for Windows
 [test_interrupted_reflow.html]
 [test_group_keyboard.html]

--- a/mobile/android/components/extensions/test/mochitest/mochitest.ini
+++ b/mobile/android/components/extensions/test/mochitest/mochitest.ini
@@ -7,17 +7,17 @@ support-files =
   context_tabs_onUpdated_iframe.html
   context_tabs_onUpdated_page.html
   file_bypass_cache.sjs
   file_dummy.html
   file_iframe_document.html
   file_slowed_document.sjs
   head.js
 tags = webextensions
-skip-if = !is_fennec
+skip-if = !isFennec
 
 [test_ext_all_apis.html]
 [test_ext_downloads_saveAs.html]
 [test_ext_tab_runtimeConnect.html]
 [test_ext_tabs_captureVisibleTab.html]
 [test_ext_tabs_create.html]
 [test_ext_tabs_events.html]
 [test_ext_tabs_executeScript.html]

--- a/taskcluster/ci/test/mochitest.yml
+++ b/taskcluster/ci/test/mochitest.yml
@@ -33,20 +33,17 @@ job-defaults:
                     - unittests/win_taskcluster_unittest.py
 
 mochitest:
     description: "Mochitest plain run"
     suite: mochitest/plain-chunked
     treeherder-symbol: M()
     loopback-video: true
     run-on-projects: built-projects
-    tier:
-        by-test-platform:
-            android-em-7.*: 2
-            default: default
+    tier: default
     instance-size:
         by-test-platform:
             android-em.*: xlarge
             default: default
     virtualization:
         by-test-platform:
             windows10-64-qr/.*: virtual-with-gpu
             default: virtual

--- a/taskcluster/ci/test/test-sets.yml
+++ b/taskcluster/ci/test/test-sets.yml
@@ -373,17 +373,18 @@ android-opt-tests:
 android-x86_64-opt-tests:
     # crashtests failing on debug; bug 1524493
     - crashtest
     # geckoview-junit perma-fail on opt and debug; bug 1521195
     - geckoview-junit
 
 android-x86_64-tests:
     - jsreftest
-    - mochitest
+    # various mochitest (plain) failures; bug 1460411
+    # - mochitest
     - mochitest-clipboard
     - mochitest-gpu
     # various reftest (plain) failures; bug 1501582
     # - reftest
 
 android-x86-tests:
     - web-platform-tests
     - web-platform-tests-reftests

--- a/testing/mochitest/runtestsremote.py
+++ b/testing/mochitest/runtestsremote.py
@@ -97,17 +97,17 @@ class MochiRemote(MochitestDesktop):
             self.log.warning("unable to kill %s before running tests!" % procName)
 
         # Add Android version (SDK level) to mozinfo so that manifest entries
         # can be conditional on android_version.
         self.log.info(
             "Android sdk version '%s'; will use this to filter manifests" %
             str(self.device.version))
         mozinfo.info['android_version'] = str(self.device.version)
-        mozinfo.info['is_fennec'] = not ('geckoview' in options.app)
+        mozinfo.info['isFennec'] = not ('geckoview' in options.app)
         mozinfo.info['is_emulator'] = self.device._device_serial.startswith('emulator-')
 
     def cleanup(self, options, final=False):
         if final:
             self.device.rm(self.remoteChromeTestDir, force=True, recursive=True)
             self.chromePushed = False
             uploadDir = os.environ.get('MOZ_UPLOAD_DIR', None)
             if uploadDir and self.device.is_dir(self.remoteMozLog):

--- a/toolkit/components/extensions/test/mochitest/mochitest-common.ini
+++ b/toolkit/components/extensions/test/mochitest/mochitest-common.ini
@@ -50,17 +50,16 @@ support-files =
   slow_response.sjs
   webrequest_worker.js
   !/dom/tests/mochitest/geolocation/network_geolocation.sjs
   !/toolkit/components/passwordmgr/test/authenticate.sjs
   file_redirect_data_uri.html
 prefs =
   security.mixed_content.upgrade_display_content=false
   browser.chrome.guess_favicon=true
-skip-if = toolkit == 'android' && !is_fennec
 
 [test_ext_async_clipboard.html]
 skip-if = (toolkit == 'android') # near-permafail after landing bug 1270059: Bug 1523131
 [test_ext_background_canvas.html]
 [test_ext_background_page.html]
 skip-if = (toolkit == 'android') # android doesn't have devtools
 [test_ext_canvas_resistFingerprinting.html]
 [test_ext_clipboard.html]

--- a/toolkit/components/passwordmgr/test/mochitest/mochitest.ini
+++ b/toolkit/components/passwordmgr/test/mochitest/mochitest.ini
@@ -14,17 +14,17 @@ support-files =
   ../browser/form_autofocus_js.html
   ../browser/form_basic.html
   ../browser/formless_basic.html
   ../browser/form_cross_origin_secure_action.html
   auth2/authenticate.sjs
   pwmgr_common.js
   pwmgr_common_parent.js
   ../authenticate.sjs
-skip-if = toolkit == 'android' && !is_fennec # Don't run on GeckoView
+skip-if = toolkit == 'android' && !isFennec # Don't run on GeckoView
 
 [test_autocomplete_highlight.html]
 scheme = https
 skip-if = toolkit == 'android' # autocomplete
 [test_autocomplete_https_upgrade.html]
 skip-if = toolkit == 'android' # autocomplete
 [test_autocomplete_sandboxed.html]
 scheme = https

--- a/uriloader/exthandler/tests/mochitest/mochitest.ini
+++ b/uriloader/exthandler/tests/mochitest/mochitest.ini
@@ -5,10 +5,9 @@ support-files =
   unsafeBidi_chromeScript.js
   unsafeBidiFileName.sjs
 
 [test_handlerApps.xhtml]
 skip-if = (toolkit == 'android' || os == 'mac') || e10s # OS X: bug 786938
 scheme = https
 [test_unknown_ext_protocol_handlers.html]
 [test_unsafeBidiChars.xhtml]
-skip-if = toolkit == 'android' && !is_fennec # Bug 1525959
 [test_web_protocol_handlers.html]