--- a/layout/generic/test/chrome.ini
+++ b/layout/generic/test/chrome.ini
@@ -1,17 +1,17 @@
 [DEFAULT]
-skip-if = buildapp == 'b2g' || os == 'android'
+skip-if = os == 'android'
 support-files =
   file_bug514732_window.xul
   frame_selection_underline-ref.xhtml
   frame_selection_underline.css
   frame_selection_underline.xhtml
 
 [test_backspace_delete.xul]
 skip-if = true # Bug 1163311
 [test_bug469613.xul]
 [test_bug469774.xul]
 [test_bug508115.xul]
 [test_bug514732-2.xul]
 [test_bug632379.xul]
-skip-if = buildapp == 'mulet' || os == 'linux' # Bug 1207914 for Linux
+skip-if = os == 'linux' # Bug 1207914
 [test_selection_underline.html]

--- a/layout/generic/test/mochitest.ini
+++ b/layout/generic/test/mochitest.ini
@@ -26,127 +26,114 @@ support-files =
 support-files = bug344830_testembed.svg
 [test_bug348681.html]
 [test_bug382429.html]
 [test_bug384527.html]
 [test_bug385751.html]
 [test_bug389630.html]
 [test_bug391747.html]
 [test_bug392746.html]
-skip-if = buildapp == 'mulet' || buildapp == 'b2g' # b2g(ctrl mouse select not working in b2g) b2g-debug(ctrl mouse select not working in b2g) b2g-desktop(ctrl mouse select not working in b2g)
 [test_bug392923.html]
 [test_bug394173.html]
 [test_bug394239.html]
 [test_bug402380.html]
 [test_bug404872.html]
 [test_bug405178.html]
 [test_bug416168.html]
 [test_bug421436.html]
 [test_bug421839-1.html]
 skip-if = true # Disabled for calling finish twice
 [test_bug421839-2.html]
 support-files = bug421839-2-page.html
 [test_bug424627.html]
 [test_bug438840.html]
 [test_bug448860.html]
-skip-if = (toolkit == 'gonk' && debug) #debug-only failure
 [test_bug448987.html]
 skip-if = true # Bug 932296
 support-files = file_bug448987.html file_bug448987_ref.html file_bug448987_notref.html
 [test_bug449653.html]
 support-files = file_bug449653_1.html file_bug449653_1_ref.html
 [test_bug460532.html]
 [test_bug468167.html]
 [test_bug470212.html]
 [test_bug488417.html]
 skip-if = true # Bug 489560
 [test_bug496275.html]
-skip-if = toolkit == 'android' || buildapp == 'mulet' #CRASH_DUMP # TC: Bug 1144079 - Re-enable Mulet mochitests and reftests taskcluster-specific disables.
+skip-if = toolkit == 'android' #CRASH_DUMP
 [test_bug503813.html]
-skip-if = buildapp == 'mulet' || toolkit == 'android' #CRASH_DUMP
+skip-if = toolkit == 'android' #CRASH_DUMP
 [test_bug507902.html]
 skip-if = true # Bug 510001
 [test_bug514732.html]
-skip-if = (buildapp == 'b2g' && (toolkit != 'gonk' || debug)) || toolkit == 'android' #CRASH_DUMP # b2g-debug(times out, also on Android) b2g-desktop(times out, also on Android)
+skip-if = toolkit == 'android' #CRASH_DUMP # timeouts
 support-files = file_bug514732_1.html file_bug514732_helper.html
 [test_bug527306.html]
 [test_bug579767.html]
 support-files = file_bug579767_1.html file_bug579767_2.html
 [test_bug522632.html]
 [test_bug524925.html]
 [test_bug589621.html]
 [test_bug589623.html]
 [test_bug597333.html]
-skip-if = buildapp == 'mulet' # TC: Bug 1144079 - Re-enable Mulet mochitests and reftests taskcluster-specific disables.
 [test_bug633762.html]
-skip-if = buildapp == 'mulet' # TC: Bug 1144079 - Re-enable Mulet mochitests and reftests taskcluster-specific disables.
 support-files = bug633762_iframe.html
 [test_bug666225.html]
-skip-if = buildapp == 'mulet' # TC: Bug 1144079 - Re-enable Mulet mochitests and reftests taskcluster-specific disables.
 [test_bug719503.html]
 [test_bug719515.html]
 [test_bug719518.html]
 [test_bug719523.html]
 [test_bug735641.html]
-skip-if = (buildapp == 'b2g' && toolkit != 'gonk') #Bug 931116, b2g desktop specific, initial triage
 [test_bug748961.html]
 [test_bug756984.html]
 [test_bug784410.html]
-skip-if = buildapp == 'b2g' #Bug 931116, 1129060 no wheel events on b2g
 [test_bug785324.html]
 [test_bug791616.html]
-skip-if = buildapp == 'b2g' # b2g(Target should not have scrolled - got 114.10000610351562, expected 115.39999389648438) b2g-debug(Target should not have scrolled - got 114.10000610351562, expected 115.39999389648438) b2g-desktop(Target should not have scrolled - got 114.10000610351562, expected 115.39999389648438)
 [test_bug831780.html]
 [test_bug841361.html]
 [test_bug904810.html]
 [test_bug938772.html]
 [test_bug970363.html]
 [test_bug1062406.html]
 [test_bug1174521.html]
 [test_bug1198135.html]
 [test_bug1307853.html]
 support-files = file_bug1307853.html
 [test_contained_plugin_transplant.html]
 skip-if = os=='win'
 [test_image_selection.html]
 [test_image_selection_2.html]
 [test_invalidate_during_plugin_paint.html]
-skip-if = buildapp == 'mulet' || buildapp == 'b2g' || toolkit == 'android' # b2g(plugins not supported) b2g-debug(plugins not supported) b2g-desktop(plugins not supported)
+skip-if = toolkit == 'android'
 [test_intrinsic_size_on_loading.html]
 [test_movement_by_characters.html]
 [test_movement_by_words.html]
 # Disable the caret movement by word test on Linux because the shortcut keys
 # are defined in system level.  So, it depends on the environment.
 # Disable on Windows for too many intermittent failures (bug 916143).
 skip-if = (toolkit == "gtk2") || (toolkit == "gtk3") || (os == "win")
 [test_overflow_event.html]
 [test_page_scroll_with_fixed_pos.html]
-skip-if = buildapp == 'mulet' || (buildapp == 'b2g' && (toolkit != 'gonk' || debug)) # b2g-debug(opened window too small?) b2g-desktop(opened window too small?)
 support-files = page_scroll_with_fixed_pos_window.html
 [test_plugin_clipping.xhtml]
-skip-if = (buildapp == 'b2g' && toolkit != 'gonk') || e10s #Bug 931116, b2g desktop specific, initial triage
+skip-if = e10s
 [test_plugin_clipping2.xhtml]
-skip-if = (buildapp == 'b2g' && toolkit != 'gonk') || e10s #Bug 931116, b2g desktop specific, initial triage
+skip-if = e10s
 [test_plugin_clipping_transformed.xhtml]
-skip-if = (buildapp == 'b2g' && toolkit != 'gonk') || e10s #Bug 931116, b2g desktop specific, initial triage
+skip-if = e10s
 [test_plugin_clipping_table.xhtml]
-skip-if = (buildapp == 'b2g' && toolkit != 'gonk') || e10s #Bug 931116, b2g desktop specific, initial triage
+skip-if = e10s
 [test_plugin_focus.html]
-skip-if = buildapp == 'mulet' || buildapp == 'b2g' # b2g(plugins not supported) b2g-debug(plugins not supported) b2g-desktop(plugins not supported)
 [test_plugin_mouse_coords.html]
-skip-if = buildapp == 'mulet' || buildapp == 'b2g' || toolkit == 'android' # b2g(plugins not supported) b2g-debug(plugins not supported) b2g-desktop(plugins not supported)
+skip-if = toolkit == 'android'
 [test_plugin_position.xhtml]
 skip-if = e10s
 [test_scroll_behavior.html]
-skip-if = buildapp == 'b2g' # Bug 1062609
 [test_selection_expanding.html]
-skip-if = buildapp == 'mulet' || buildapp == 'b2g' # b2g(mouse selection not working) b2g-debug(mouse selection not working) b2g-desktop(mouse selection not working)
 support-files = selection_expanding_xbl.xml
 [test_selection_preventDefault.html]
-skip-if = buildapp == 'mulet'
 [test_selection_splitText-normalize.html]
 [test_selection_touchevents.html]
 [test_taintedfilters.html]
 support-files = file_taintedfilters_feDisplacementMap-tainted-1.svg file_taintedfilters_feDisplacementMap-tainted-2.svg file_taintedfilters_feDisplacementMap-tainted-3.svg file_taintedfilters_feDisplacementMap-tainted-ref.svg file_taintedfilters_feDisplacementMap-untainted-ref.svg file_taintedfilters_feDisplacementMap-untainted-1.svg file_taintedfilters_feDisplacementMap-untainted-2.svg file_taintedfilters_red-flood-for-feImage-cors.svg file_taintedfilters_red-flood-for-feImage-cors.svg^headers^ file_taintedfilters_red-flood-for-feImage.svg
 [test_scroll_position_restore.html]
 support-files = file_scroll_position_restore.html
 [test_scroll_animation_restore.html]
 [test_scroll_position_iframe.html]