--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -1017,17 +1017,17 @@ fuzzy-if(skiaContent,1,5) == 421632-1.ht
 != 421710-1.html about:blank
 fails-if(Android) fails-if(usesRepeatResampling) == 421885-1.xml 421885-1-ref.xml
 == 421955-1.html 421955-1-ref.html
 == 422249-1.html 422249-1-ref.html
 == 422394-1.html 422394-1-ref.html
 == 422678-1.html 422678-1-ref.html
 == 423130-1.html 423130-1-ref.html
 == 423385-1.html 423385-1-ref.html
-== 423599-1.html 423599-1-ref.html
+random-if(gtkWidget) == 423599-1.html 423599-1-ref.html # bug 1309095
 == 423676-1.html 423676-1-ref.html
 fails == 423823-1.html 423823-1-ref.html # scrolling rowgroups were removed in bug 28800
 == 424074-1.xul 424074-1-ref.xul
 fails-if(Android) != 424074-1.xul 424074-1-ref2.xul
 random-if(gtkWidget) == 424074-1-ref2.xul 424074-1-ref3.xul
 == 424236-1.html 424236-1-ref.html
 == 424236-2.html 424236-2-ref.html
 == 424236-3.html 424236-3-ref.html

--- a/layout/reftests/css-grid/reftest.list
+++ b/layout/reftests/css-grid/reftest.list
@@ -74,21 +74,21 @@ skip-if(Android) == grid-auto-min-sizing
 == grid-flex-min-sizing-002.html grid-flex-min-sizing-002-ref.html
 == grid-item-align-001.html grid-item-align-001-ref.html
 == grid-item-align-002.html grid-item-align-002-ref.html
 == grid-item-align-003.html grid-item-align-003-ref.html
 == grid-item-justify-001.html grid-item-justify-001-ref.html
 == grid-item-justify-002.html grid-item-justify-002-ref.html
 == grid-item-stretch-001.html grid-item-stretch-001-ref.html
 == grid-item-self-baseline-001.html grid-item-self-baseline-001-ref.html
-skip-if(!gtkWidget) == grid-item-content-baseline-001.html grid-item-content-baseline-001-ref.html # depends on exact Ahem baseline font metrics which seems to differ between platforms
-skip-if(!gtkWidget) == grid-item-content-baseline-002.html grid-item-content-baseline-002-ref.html # ditto
-skip-if(!gtkWidget) == grid-item-mixed-baseline-001.html grid-item-mixed-baseline-001-ref.html # ditto
-skip-if(!gtkWidget) == grid-item-mixed-baseline-002.html grid-item-mixed-baseline-002-ref.html # ditto
-skip-if(!gtkWidget) == grid-item-mixed-baseline-003.html grid-item-mixed-baseline-003-ref.html # ditto
+random-if(http.oscpu!="Linux\u0020i686") == grid-item-content-baseline-001.html grid-item-content-baseline-001-ref.html # depends on exact Ahem baseline font metrics which seems to differ between platforms: bug 1310792
+random-if(http.oscpu!="Linux\u0020i686") == grid-item-content-baseline-002.html grid-item-content-baseline-002-ref.html # ditto
+random-if(http.oscpu!="Linux\u0020i686") == grid-item-mixed-baseline-001.html grid-item-mixed-baseline-001-ref.html # ditto
+random-if(http.oscpu!="Linux\u0020i686") == grid-item-mixed-baseline-002.html grid-item-mixed-baseline-002-ref.html # ditto
+random-if(http.oscpu!="Linux\u0020i686") == grid-item-mixed-baseline-003.html grid-item-mixed-baseline-003-ref.html # ditto
 skip-if(!gtkWidget) == grid-item-mixed-baseline-004.html grid-item-mixed-baseline-004-ref.html # ditto
 == grid-align-content-001.html grid-align-content-001-ref.html
 == grid-justify-content-001.html grid-justify-content-001-ref.html
 skip-if(Android&&isDebugBuild) == grid-justify-content-002.html grid-justify-content-002-ref.html # Bug 1245884 - slow
 skip-if(Android&&isDebugBuild) == grid-justify-content-003.html grid-justify-content-003-ref.html # Bug 1245884 - slow
 skip-if(!gtkWidget) == grid-container-baselines-001.html grid-container-baselines-001-ref.html
 skip-if(!gtkWidget) == grid-container-baselines-002.html grid-container-baselines-002-ref.html
 skip-if(!gtkWidget) == grid-container-baselines-003.html grid-container-baselines-003-ref.html

--- a/layout/reftests/first-letter/reftest.list
+++ b/layout/reftests/first-letter/reftest.list
@@ -59,16 +59,16 @@ HTTP(..) == 329069-5.html 329069-5-ref.h
 == 469227-1.html 469227-1-ref.html
 == 484400-1.html 484400-1-ref.html
 == 594303-1.html 594303-1-ref.html
 fails-if(winWidget||cocoaWidget) == 617869-1.html 617869-1-ref.html
 == 723509-1.html 723509-1-ref.html
 == 922550-1.html 922550-1-ref.html
 == 958249.html 958249-ref.html
 == font-text-styles.html font-text-styles-ref.html
-fails-if(gtkWidget) random-if(winWidget&&!d2d) == font-text-styles-floater.html font-text-styles-floater-ref.html # bug 992846
+random-if(gtkWidget) random-if(winWidget&&!d2d) == font-text-styles-floater.html font-text-styles-floater-ref.html # bug 992846
 == inline-height-empty.html inline-height-empty-ref.html
 HTTP(..) == indic-clusters-1.html indic-clusters-1-ref.html
 == overflow-float-nooverflow.html overflow-float-nooverflow-ref.html
 == overflow-float-overflow.html overflow-float-overflow-notref.html
 == overflow-inline-nooverflow.html overflow-inline-nooverflow-ref.html
 != overflow-inline-overflow.html overflow-inline-overflow-notref.html
 == overflow-inline-overflow.html overflow-inline-overflow-ref.html

--- a/layout/reftests/flexbox/reftest.list
+++ b/layout/reftests/flexbox/reftest.list
@@ -9,19 +9,20 @@
 # tests over to the w3c-css directory, so that they can become part of the
 # W3C's test suite.
 
 # SUBDIRECTORY: Reftests for paginated flex containers
 include pagination/reftest.list
 
 # Tests for cross-axis alignment (align-self / align-items properties)
 fails == flexbox-align-self-baseline-horiz-2.xhtml  flexbox-align-self-baseline-horiz-2-ref.xhtml # bug 793456, and possibly others
-# This one fails on windows R (but not Ru, strangely). On Windows R, the
-# single-line <label> flex item has a different background size in test vs. ref
-fuzzy-if(cocoaWidget,1,2) random-if(winWidget) == flexbox-align-self-baseline-horiz-3.xhtml  flexbox-align-self-baseline-horiz-3-ref.xhtml # XXXdholbert investigate
+# This one fails on windows R (but not Ru, strangely) and GTK.
+# On Windows R and GTK, the single-line <label> flex item has a different
+# background size in test vs. ref
+fuzzy-if(cocoaWidget,1,2) random-if(winWidget||gtkWidget) == flexbox-align-self-baseline-horiz-3.xhtml  flexbox-align-self-baseline-horiz-3-ref.xhtml # XXXdholbert investigate
 == flexbox-align-self-baseline-horiz-4.xhtml flexbox-align-self-baseline-horiz-4-ref.xhtml
 
 # Tests for box-sizing on flex containers and flex items.
 == flexbox-box-sizing-on-container-horiz-1.html flexbox-box-sizing-on-container-horiz-1-ref.html
 == flexbox-box-sizing-on-container-vert-1.html flexbox-box-sizing-on-container-vert-1-ref.html
 == flexbox-box-sizing-on-items-horiz-1a.html flexbox-box-sizing-on-items-horiz-1-ref.html
 == flexbox-box-sizing-on-items-horiz-1b.html flexbox-box-sizing-on-items-horiz-1-ref.html
 == flexbox-box-sizing-on-items-vert-1a.html flexbox-box-sizing-on-items-vert-1-ref.html

--- a/layout/reftests/font-face/reftest.list
+++ b/layout/reftests/font-face/reftest.list
@@ -1,28 +1,28 @@
 # Tests using downloaded fonts use HTTP(..) because they use fonts in
 # ../fonts/.  We can't use file:/// URLs because of cross-directory access
 # restrictions on file: URLs.
 
 HTTP(..) != download-1.html download-1-notref.html
 HTTP(..) == download-2.html download-2-ref.html
 HTTP(..) != download-2.html about:blank
-random-if(winWidget) HTTP(..) == download-2-big.html download-2-big-otf.html # bug 470713
+random-if(winWidget||gtkWidget) HTTP(..) == download-2-big.html download-2-big-otf.html # bug 470713
 HTTP(..) != download-2-big-otf.html about:blank
 asserts-if(Android&&!asyncPan,1-8) HTTP(..) != download-3-notref.html download-3.html # bug 1019192
 asserts-if(Android,0-8) HTTP(..) == download-3-ref.html download-3.html # same bugs as above
 asserts-if(Android,0-8) HTTP(..) == fallback-to-system-1.html fallback-to-system-1-ref.html # just delayed assertions from above tests
 HTTP(..) == name-override-simple-1.html name-override-simple-1-ref.html
 HTTP(..) != name-override-simple-1.html download-1-notref.html
 fails HTTP(..) == name-override-1.html name-override-1-ref.html
 HTTP(..) == multiple-descriptor-1.html multiple-descriptor-1-ref.html
 HTTP(..) != multiple-descriptor-1.html multiple-descriptor-1-notref.html
 HTTP(..) == src-list-1.html src-list-1-ref.html
 HTTP(..) == src-list-2.html src-list-2-ref.html
-random-if(winWidget) HTTP(..) == src-list-2-big-otf.html src-list-2-big-ref.html # bug 470713
+random-if(winWidget||gtkWidget) HTTP(..) == src-list-2-big-otf.html src-list-2-big-ref.html # bug 470713
 HTTP(..) == src-list-format-1.html src-list-format-1-ref.html
 HTTP(..) == src-list-format-2.html src-list-format-2-ref.html
 HTTP(..) == src-list-format-3.html src-list-format-3-ref.html
 HTTP(..) == src-list-format-4.html src-list-format-1-ref.html
 HTTP(..) == src-list-format-5.html src-list-format-2-ref.html
 HTTP(..) == src-list-format-6.html src-list-format-3-ref.html
 # assumes AAT fonts are only supported on MacOS
 random-if(cocoaWidget) HTTP(..) == src-list-format-7.html src-list-format-2-ref.html

--- a/layout/reftests/font-matching/reftest.list
+++ b/layout/reftests/font-matching/reftest.list
@@ -45,17 +45,17 @@ random-if(cocoaWidget) != impact-bold.ht
 
 # localized font family names should always match just as English names do
 == localized-family-names-001.html localized-family-names-001-ref.html
 == localized-family-names-002.html localized-family-names-002-ref.html
 == localized-family-names-003.html localized-family-names-003-ref.html
 == localized-family-names-004.html localized-family-names-004-ref.html
 
 # family names with escaped spaces shouldn't match the names without the spaces
-== familyname-escapedidents.html familyname-escapedidents-ref.html
+fails-if(http.oscpu=="Linux\u0020x86_64") == familyname-escapedidents.html familyname-escapedidents-ref.html # bug 1309425
 
 # weight mapping tests
 HTTP(..) == normalmedium.html normalmedium-ref.html
 HTTP(..) != normalmedium.html normalmedium-notref.html
 
 # Linux fails due to bug 604815
 fuzzy-if(OSX==1010&&browserIsRemote,1,23) HTTP(..) == weightmapping-12.html weightmapping-12-ref.html
 HTTP(..) == weightmapping-25.html weightmapping-25-ref.html

--- a/layout/reftests/mathml/reftest.list
+++ b/layout/reftests/mathml/reftest.list
@@ -1,11 +1,11 @@
 == dir-1.html dir-1-ref.html
 == dir-2.html dir-2-ref.html
-== dir-3.html dir-3-ref.html
+random-if(gtkWidget) == dir-3.html dir-3-ref.html # bug 1309426
 == dir-4.html dir-4-ref.html
 == dir-5.html dir-5-ref.html
 == dir-6.html dir-6-ref.html
 == dir-6a.html dir-6a-ref.html
 == dir-7.html dir-7-ref.html
 fails == dir-8.html dir-8-ref.html
 fails == dir-9.html dir-9-ref.html # Bug 787215
 == dir-10.html dir-10-ref.html
@@ -37,18 +37,18 @@ random-if(smallScreen&&Android) fuzzy(25
 == mfenced-5b.xhtml mfenced-5-ref.xhtml
 == mfenced-5c.xhtml mfenced-5-ref.xhtml
 == mfenced-5d.xhtml mfenced-5-ref.xhtml
 == mfenced-6.html mfenced-6-ref.html
 == mfenced-7.html mfenced-7-ref.html
 != mfenced-8.html mfenced-8-ref.html
 == mfenced-9.html mfenced-9-ref.html
 fails-if(/^Windows\x20NT\x205\.1/.test(http.oscpu)) == mfenced-10.html mfenced-10-ref.html # Windows versions without Cambria Math, see bug 670592
-== mfenced-11.html mfenced-11-ref.html
-== mfenced-12.html mfenced-12-ref.html
+fails-if(http.oscpu=="Linux\u0020x86_64") == mfenced-11.html mfenced-11-ref.html # bug 670592
+fails-if(http.oscpu=="Linux\u0020x86_64") == mfenced-12.html mfenced-12-ref.html # bug 670592
 == mi-mathvariant-1.xhtml mi-mathvariant-1-ref.xhtml
 == mi-mathvariant-2.xhtml mi-mathvariant-2-ref.xhtml
 != mi-mathvariant-3.html mi-mathvariant-3-ref.html
 != non-spacing-accent-1.xhtml non-spacing-accent-1-ref.xhtml
 == overbar-width-1.xhtml overbar-width-1-ref.xhtml
 == quotes-1.xhtml quotes-1-ref.xhtml
 != stretchy-underbar-1.xhtml stretchy-underbar-1-ref.xhtml
 != stretchy-munderover-1a.html stretchy-munderover-1-ref.html
@@ -108,17 +108,17 @@ fails == stretchy-mover-2a.html stretchy
 != embellished-op-3-3.html embellished-op-3-3-ref.html
 != embellished-op-3-4.html embellished-op-3-4-ref.html
 != embellished-op-3-5.html embellished-op-3-5-ref.html
 == embellished-op-4-1.html embellished-op-4-1-ref.html
 == embellished-op-4-2.html embellished-op-4-2-ref.html
 == embellished-op-4-3.html embellished-op-4-3-ref.html
 == embellished-op-5-1.html embellished-op-5-ref.html
 == embellished-op-5-2.html embellished-op-5-ref.html
-random-if(winWidget&&!/^Windows\x20NT\x205\.1/.test(http.oscpu)) == semantics-1.xhtml semantics-1-ref.xhtml # Windows versions with Cambria Math
+fails-if(http.oscpu=="Linux\u0020x86_64") random-if(winWidget&&!/^Windows\x20NT\x205\.1/.test(http.oscpu)) == semantics-1.xhtml semantics-1-ref.xhtml # Windows versions with Cambria Math, Linux x86_64:bug 1309429
 == semantics-2.html semantics-2-ref.html
 == semantics-3.html semantics-3-ref.html
 == semantics-4.html semantics-4-ref.html
 != mathcolor-1.xml mathcolor-1-ref.xml
 != mathcolor-2.xml mathcolor-2-ref.xml
 != mathcolor-3.xml mathcolor-3-ref.xml
 == mathcolor-4.xml mathcolor-4-ref.xml
 != mathbackground-1.xml mathbackground-1-ref.xml
@@ -139,19 +139,19 @@ fails-if(skiaContent&&OSX>=1010) == scal
 == mspace-1.html mspace-1-ref.html
 == mpadded-1.html mpadded-1-ref.html
 == mpadded-2.html mpadded-2-ref.html
 == mpadded-3.html mpadded-3-ref.html
 == mpadded-4.html mpadded-4-ref.html
 == mpadded-5.html mpadded-5-ref.html
 == mpadded-1-2.html mpadded-1-2-ref.html
 == mpadded-6.html mpadded-6-ref.html
-== mpadded-7.html mpadded-7-ref.html
-== mpadded-8.html mpadded-8-ref.html
-== mpadded-9.html mpadded-9-ref.html
+random-if(gtkWidget) == mpadded-7.html mpadded-7-ref.html # bug 1309430
+random-if(gtkWidget) == mpadded-8.html mpadded-8-ref.html # bug 1309430
+random-if(gtkWidget) == mpadded-9.html mpadded-9-ref.html # bug 1309430
 == math-display.html math-display-ref.html
 == scriptlevel-1.html scriptlevel-1-ref.html
 == scriptlevel-movablelimits-1.html scriptlevel-movablelimits-1-ref.html
 == munderover-align-accent-false.html munderover-align-accent-false-ref.html
 == munderover-align-accent-true.html munderover-align-accent-true-ref.html
 == munder-mover-align-accent-true.html munder-mover-align-accent-true-ref.html
 == munder-mover-align-accent-false.html munder-mover-align-accent-false-ref.html
 == mfrac-linethickness-1.xhtml mfrac-linethickness-1-ref.xhtml
@@ -187,17 +187,17 @@ fails-if(skiaContent&&OSX>=1010) == scal
 == maction-dynamic-1.html maction-dynamic-1-ref.html # bug 773482
 == maction-dynamic-2.html maction-dynamic-2-ref.html
 == mo-lspace-rspace.html mo-lspace-rspace-ref.html
 == mo-lspace-rspace-2.html mo-lspace-rspace-2-ref.html
 == mo-lspace-rspace-3.html mo-lspace-rspace-3-ref.html
 == mo-lspace-rspace-4.html mo-lspace-rspace-4-ref.html
 == mo-invisibleoperators.html mo-invisibleoperators-ref.html
 == mo-invisibleoperators-2.html mo-invisibleoperators-2-ref.html
-== mo-glyph-size.html mo-glyph-size-ref.html
+random-if(gtkWidget) == mo-glyph-size.html mo-glyph-size-ref.html # bug 1309426
 == maction-dynamic-3.html maction-dynamic-3-ref.html # bug 773482
 == whitespace-trim-1.html whitespace-trim-1-ref.html
 == whitespace-trim-2.html whitespace-trim-2-ref.html
 == whitespace-trim-3.html whitespace-trim-3-ref.html
 fails == whitespace-trim-4.html whitespace-trim-4-ref.html # Bug 787215
 == whitespace-trim-5.html whitespace-trim-5-ref.html
 random-if(winWidget&&!d2d) == opentype-stretchy.html opentype-stretchy-ref.html
 == opentype-fraction-dynamic-linethickness.html opentype-fraction-dynamic-linethickness-ref.html
@@ -219,31 +219,31 @@ fuzzy-if(skiaContent,1,80) fails-if(winW
 != menclose-1j.html menclose-1-ref.html
 != menclose-1k.html menclose-1-ref.html
 != menclose-1l.html menclose-1-ref.html
 != menclose-1m.html menclose-1-ref.html
 != menclose-1n.html menclose-1-ref.html
 != menclose-1o.html menclose-1-ref.html
 != menclose-1p.html menclose-1-ref.html
 != menclose-1q.html menclose-1-ref.html
-== menclose-2-actuarial.html menclose-2-actuarial-ref.html
-== menclose-2-bottom.html menclose-2-bottom-ref.html
-== menclose-2-box.html menclose-2-box-ref.html
+random-if(gtkWidget) == menclose-2-actuarial.html menclose-2-actuarial-ref.html # bug 1309426
+random-if(gtkWidget) == menclose-2-bottom.html menclose-2-bottom-ref.html # bug 1309426
+random-if(gtkWidget) == menclose-2-box.html menclose-2-box-ref.html # bug 1309426
 == menclose-2-circle.html menclose-2-circle-ref.html
 == menclose-2-downdiagonalstrike.html menclose-2-downdiagonalstrike-ref.html
 == menclose-2-horizontalstrike.html menclose-2-horizontalstrike-ref.html
 == menclose-2-left.html menclose-2-left-ref.html
 fuzzy-if(skiaContent,80,5) == menclose-2-longdiv.html menclose-2-longdiv-ref.html
-== menclose-2-right.html menclose-2-right-ref.html
-== menclose-2-roundedbox.html menclose-2-roundedbox-ref.html
+random-if(gtkWidget) == menclose-2-right.html menclose-2-right-ref.html # bug 1309426
+random-if(gtkWidget) == menclose-2-roundedbox.html menclose-2-roundedbox-ref.html # bug 1309426
 == menclose-2-top.html menclose-2-top-ref.html
-== menclose-2-updiagonalarrow.html menclose-2-updiagonalarrow-ref.html
+random-if(gtkWidget) == menclose-2-updiagonalarrow.html menclose-2-updiagonalarrow-ref.html # bug 1309426
 == menclose-2-updiagonalstrike.html menclose-2-updiagonalstrike-ref.html
 == menclose-2-verticalstrike.html menclose-2-verticalstrike-ref.html
-== menclose-2-roundedbox.html menclose-2-roundedbox-ref.html
+random-if(gtkWidget) == menclose-2-roundedbox.html menclose-2-roundedbox-ref.html # bug 1309426
 == menclose-2-phasorangle.html menclose-2-phasorangle-ref.html
 == menclose-3-box.html menclose-3-box-ref.html
 == menclose-3-madruwb.html menclose-3-madruwb-ref.html
 fails-if(Android||OSX==1006) == menclose-3-radical.html menclose-3-radical-ref.html # Bug 973917
 == menclose-3-default.html menclose-3-default-ref.html
 == menclose-3-invalid.html menclose-3-invalid-ref.html
 == menclose-3-multiple.html menclose-3-multiple-ref.html
 == menclose-3-unknown.html menclose-3-unknown.html
@@ -313,17 +313,17 @@ fails-if(Android||/^Windows\x20NT\x205\.
 != columnlines-3-1.html columnlines-3-1-ref.html
 == columnlines-3-2.html columnlines-3-2-ref.html
 == rowlines-1a.html rowlines-1-ref.html
 != rowlines-1b.html rowlines-1-ref.html
 != rowlines-1c.html rowlines-1-ref.html
 == rowlines-2a.html rowlines-2-ref.html
 == rowlines-2b.html rowlines-2-ref.html
 != rowlines-3-1.html rowlines-3-1-ref.html
-== rowlines-3-2.html rowlines-3-2-ref.html
+random-if(gtkWidget) == rowlines-3-2.html rowlines-3-2-ref.html # bug 1309426
 == tablespacing-1.html tablespacing-1-ref.html
 == tablespacing-2.html tablespacing-2-ref.html
 == tablespacing-3.html tablespacing-3-ref.html
 == tablespacing-4.html tablespacing-4-ref.html
 == tablespacing-5.html tablespacing-5-ref.html
 == tablespacing-5a.html tablespacing-5a-ref.html
 == tablespacing-6.html tablespacing-6-ref.html
 == tablespacing-7.html tablespacing-7-ref.html

--- a/layout/reftests/text-overflow/reftest.list
+++ b/layout/reftests/text-overflow/reftest.list
@@ -1,33 +1,33 @@
 == ellipsis-font-fallback.html ellipsis-font-fallback-ref.html
 == line-clipping.html line-clipping-ref.html
 fuzzy-if(Android,16,244) HTTP(..) == marker-basic.html marker-basic-ref.html  # Bug 1128229
 HTTP(..) == marker-string.html marker-string-ref.html
 skip-if(Android) HTTP(..) == bidi-simple.html bidi-simple-ref.html # Fails on Android due to anti-aliasing
 skip-if(!gtkWidget) fuzzy-if(gtkWidget,2,289) HTTP(..) == bidi-simple-scrolled.html bidi-simple-scrolled-ref.html # Fails on Windows and OSX due to anti-aliasing
 fuzzy-if(Android,24,4000) fuzzy-if(cocoaWidget,1,40) fuzzy-if(asyncPan&&!layersGPUAccelerated,121,1836) HTTP(..) == scroll-rounding.html scroll-rounding-ref.html # bug 760264
-fuzzy(2,453) fuzzy-if(skiaContent,9,2100) HTTP(..) == anonymous-block.html anonymous-block-ref.html
+fuzzy(2,453) fuzzy-if(skiaContent,9,2100) fails-if(gtkWidget) HTTP(..) == anonymous-block.html anonymous-block-ref.html # gtkWidget:bug 1309103
 HTTP(..) == false-marker-overlap.html false-marker-overlap-ref.html
 HTTP(..) == visibility-hidden.html visibility-hidden-ref.html
 fuzzy-if(asyncPan&&!layersGPUAccelerated,102,1724) fuzzy-if(gtkWidget,10,8) HTTP(..) == block-padding.html block-padding-ref.html
 HTTP(..) == quirks-decorations.html quirks-decorations-ref.html
 HTTP(..) == quirks-line-height.html quirks-line-height-ref.html
 HTTP(..) == standards-decorations.html standards-decorations-ref.html
 HTTP(..) == standards-line-height.html standards-line-height-ref.html
 random-if(/^Windows\x20NT\x205\.1/.test(http.oscpu)) fuzzy-if(skiaContent,1,4200) HTTP(..) == selection.html selection-ref.html # bug 668849
 HTTP(..) == marker-shadow.html marker-shadow-ref.html
 == aligned-baseline.html aligned-baseline-ref.html
 skip-if(Android) fuzzy-if(skiaContent,1,5) == clipped-elements.html clipped-elements-ref.html
 HTTP(..) == theme-overflow.html theme-overflow-ref.html
 HTTP(..) == table-cell.html table-cell-ref.html
 fuzzy-if(gtkWidget,10,32) HTTP(..) == two-value-syntax.html two-value-syntax-ref.html
 HTTP(..) == single-value.html single-value-ref.html
 fuzzy-if(gtkWidget,10,2) HTTP(..) == atomic-under-marker.html atomic-under-marker-ref.html
-fuzzy(1,2616) skip-if(Android) fuzzy-if(asyncPan&&!layersGPUAccelerated,102,12352) HTTP(..) == xulscroll.html xulscroll-ref.html
+fuzzy(1,2616) skip-if(Android) fuzzy-if(asyncPan&&!layersGPUAccelerated,102,12352) fails-if(http.oscpu=="Linux\u0020x86_64") HTTP(..) == xulscroll.html xulscroll-ref.html # Linux x86_64:bug 1309107
 HTTP(..) == combobox-zoom.html combobox-zoom-ref.html
 
 # The vertical-text pref setting can be removed after bug 1138384 lands
 == vertical-decorations-1.html vertical-decorations-1-ref.html
 == vertical-decorations-2.html vertical-decorations-2-ref.html
 != vertical-decorations-1.html vertical-decorations-1-2-notref.html
 != vertical-decorations-2.html vertical-decorations-1-2-notref.html
 == vertical-decorations-3.html vertical-decorations-3-ref.html

--- a/layout/reftests/text/reftest.list
+++ b/layout/reftests/text/reftest.list
@@ -139,17 +139,17 @@ fuzzy-if(gtkWidget,1,177) fuzzy-if(skiaC
 != overflowwrap-09.html wordwrap-01-ref.html
 == wordwrap-09.html wordwrap-09-ref.html
 == overflowwrap-09.html wordwrap-09-ref.html
 == wordwrap-10.html wordwrap-10-ref.html # bug 752459
 == overflowwrap-10.html wordwrap-10-ref.html
 == word-spacing-01.html word-spacing-01-ref.html
 # the following will fail when rendering with Core Text (see bug 389074) due to what appears to be
 # an Apple bug: the presence of ZWNJ disturbs the positioning of an adjacent glyph. rdar://6427865
-random-if(cocoaWidget) HTTP(..) == zwnj-01.xhtml zwnj-01-ref.xhtml
+random-if(cocoaWidget) random-if(gtkWidget) HTTP(..) == zwnj-01.xhtml zwnj-01-ref.xhtml # gtkWidget:bug 1309113
 HTTP(..) == zwnj-02.xhtml zwnj-02-ref.xhtml # HTTP(..) for ../filters.svg
 != zwnj-01.html zwnj-01-notref.html
 == initial-zwj-1.html initial-zwj-1-ref.html
 == cgj-01.html cgj-01-ref.html
 == 444656.html 444656-ref.html
 == 449555-1.html 449555-1-ref.html
 == 467722.html 467722-ref.html
 fuzzy-if(skiaContent,1,600) HTTP(..) == 475092-sub.html 475092-ref.html