--- a/layout/reftests/async-scrolling/reftest.list
+++ b/layout/reftests/async-scrolling/reftest.list
@@ -20,46 +20,46 @@ skip-if(!asyncPan) == position-fixed-2.h
 skip-if(!asyncPan) == position-fixed-body.html position-fixed-body-ref.html
 skip-if(!asyncPan) == position-fixed-cover-1.html position-fixed-cover-1-ref.html
 skip-if(!asyncPan) == position-fixed-cover-2.html position-fixed-cover-2-ref.html
 skip-if(!asyncPan) == position-fixed-cover-3.html position-fixed-cover-3-ref.html
 fuzzy-if(Android,5,4) skip-if(!asyncPan) == position-fixed-transformed-1.html position-fixed-transformed-1-ref.html
 skip-if(!asyncPan) == split-layers-1.html split-layers-1-ref.html
 skip-if(!asyncPan) == split-layers-multi-scrolling-1.html split-layers-multi-scrolling-1-ref.html
 fuzzy-if(skiaContent,2,240000) fuzzy-if(browserIsRemote&&!skiaContent&&(cocoaWidget||winWidget),1,240000) skip-if(!asyncPan) == split-opacity-layers-1.html split-opacity-layers-1-ref.html
-skip-if(!asyncPan) == sticky-pos-scrollable-1.html sticky-pos-scrollable-1-ref.html
+fails-if(webrender) skip-if(!asyncPan) == sticky-pos-scrollable-1.html sticky-pos-scrollable-1-ref.html # bug 1366295 for webrender
 skip-if(!asyncPan) == sticky-pos-scrollable-2.html sticky-pos-scrollable-2-ref.html
-skip-if(!asyncPan) == sticky-pos-scrollable-3.html sticky-pos-scrollable-3-ref.html
+fails-if(webrender) skip-if(!asyncPan) == sticky-pos-scrollable-3.html sticky-pos-scrollable-3-ref.html # bug 1366295 for webrender
 skip-if(!asyncPan) == fixed-pos-scrollable-1.html fixed-pos-scrollable-1-ref.html
 skip-if(!asyncPan) == culling-1.html culling-1-ref.html
 skip-if(!asyncPan) == position-fixed-iframe-1.html position-fixed-iframe-1-ref.html
 skip-if(!asyncPan) == position-fixed-iframe-2.html position-fixed-iframe-2-ref.html
 fuzzy-if(skiaContent,1,11300) skip-if(!asyncPan) == position-fixed-in-scroll-container.html position-fixed-in-scroll-container-ref.html
 skip-if(!asyncPan) == position-fixed-inside-sticky-1.html position-fixed-inside-sticky-1-ref.html
 skip-if(!asyncPan) == position-fixed-inside-sticky-2.html position-fixed-inside-sticky-2-ref.html
 fuzzy(1,60000) skip-if(!asyncPan) == group-opacity-surface-size-1.html group-opacity-surface-size-1-ref.html
-skip-if(!asyncPan) == position-sticky-transformed.html position-sticky-transformed-ref.html
+fails-if(webrender) skip-if(!asyncPan) == position-sticky-transformed.html position-sticky-transformed-ref.html # bug 1366295 for webrender
 skip-if(!asyncPan) == offscreen-prerendered-active-opacity.html offscreen-prerendered-active-opacity-ref.html
 fuzzy-if(Android,6,4) fuzzy-if(skiaContent&&!Android,1,34) skip-if(!asyncPan) == offscreen-clipped-blendmode-1.html offscreen-clipped-blendmode-ref.html
 fuzzy-if(Android,6,4) skip-if(!asyncPan) == offscreen-clipped-blendmode-2.html offscreen-clipped-blendmode-ref.html
 fuzzy-if(Android,6,4) skip == offscreen-clipped-blendmode-3.html offscreen-clipped-blendmode-ref.html # bug 1251588 - wrong AGR on mix-blend-mode item
 fuzzy-if(Android,6,4) skip-if(!asyncPan) == offscreen-clipped-blendmode-4.html offscreen-clipped-blendmode-ref.html
-fuzzy-if(Android,7,4) skip-if(!asyncPan) == perspective-scrolling-1.html perspective-scrolling-1-ref.html
-fuzzy-if(Android,7,4) skip-if(!asyncPan) == perspective-scrolling-2.html perspective-scrolling-2-ref.html
-fuzzy-if(Android,7,4) skip-if(!asyncPan) == perspective-scrolling-3.html perspective-scrolling-3-ref.html
-fuzzy-if(Android,7,4) skip-if(!asyncPan) == perspective-scrolling-4.html perspective-scrolling-4-ref.html
+fuzzy-if(Android,7,4) fails-if(webrender) skip-if(!asyncPan) == perspective-scrolling-1.html perspective-scrolling-1-ref.html # bug 1361720 for webrender
+fuzzy-if(Android,7,4) fails-if(webrender) skip-if(!asyncPan) == perspective-scrolling-2.html perspective-scrolling-2-ref.html # bug 1361720 for webrender
+fuzzy-if(Android,7,4) fails-if(webrender) skip-if(!asyncPan) == perspective-scrolling-3.html perspective-scrolling-3-ref.html # bug 1361720 for webrender
+fuzzy-if(Android,7,4) fails-if(webrender) skip-if(!asyncPan) == perspective-scrolling-4.html perspective-scrolling-4-ref.html # bug 1361720 for webrender
 pref(apz.disable_for_scroll_linked_effects,true) skip-if(!asyncPan) == disable-apz-for-sle-pages.html disable-apz-for-sle-pages-ref.html
 fuzzy-if(browserIsRemote&&d2d,1,19) skip-if(!asyncPan) == background-blend-mode-1.html background-blend-mode-1-ref.html
-skip-if(Android||!asyncPan) != opaque-fractional-displayport-1.html about:blank
-skip-if(Android||!asyncPan) != opaque-fractional-displayport-2.html about:blank
-fuzzy-if(Android,6,4) skip-if(!asyncPan) == fixed-pos-scrolled-clip-1.html fixed-pos-scrolled-clip-1-ref.html
-fuzzy-if(Android,6,8) skip-if(!asyncPan) == fixed-pos-scrolled-clip-2.html fixed-pos-scrolled-clip-2-ref.html
-fuzzy-if(Android,6,8) skip-if(!asyncPan) == fixed-pos-scrolled-clip-3.html fixed-pos-scrolled-clip-3-ref.html
-fuzzy-if(Android,6,8) skip-if(!asyncPan) == fixed-pos-scrolled-clip-4.html fixed-pos-scrolled-clip-4-ref.html
-fuzzy-if(Android,6,4) skip-if(!asyncPan) == position-sticky-scrolled-clip-1.html position-sticky-scrolled-clip-1-ref.html
+random-if(webrender) skip-if(Android||!asyncPan) != opaque-fractional-displayport-1.html about:blank    # test is specific to "layers" and not valid with webrender
+random-if(webrender) skip-if(Android||!asyncPan) != opaque-fractional-displayport-2.html about:blank    # test is specific to "layers" and not valid with webrender
+fuzzy-if(Android,6,4) fails-if(webrender) skip-if(!asyncPan) == fixed-pos-scrolled-clip-1.html fixed-pos-scrolled-clip-1-ref.html   # bug 1373802 for webrender
+fuzzy-if(Android,6,8) fails-if(webrender) skip-if(!asyncPan) == fixed-pos-scrolled-clip-2.html fixed-pos-scrolled-clip-2-ref.html   # bug 1373802 for webrender
+fuzzy-if(Android,6,8) fails-if(webrender) skip-if(!asyncPan) == fixed-pos-scrolled-clip-3.html fixed-pos-scrolled-clip-3-ref.html   # bug 1373802 for webrender
+fuzzy-if(Android,6,8) fails-if(webrender) skip-if(!asyncPan) == fixed-pos-scrolled-clip-4.html fixed-pos-scrolled-clip-4-ref.html   # bug 1373802 for webrender
+fuzzy-if(Android,6,4) fails-if(webrender) skip-if(!asyncPan) == position-sticky-scrolled-clip-1.html position-sticky-scrolled-clip-1-ref.html # bug 1366295 for webrender
 fuzzy-if(Android,6,4) skip == position-sticky-scrolled-clip-2.html position-sticky-scrolled-clip-2-ref.html # bug ?????? - incorrectly applying clip to sticky contents
 
 # for the following tests, we want to disable the low-precision buffer
 # as it will expand the displayport beyond what the test specifies in
 # its reftest-displayport attributes, and interfere with where we expect
 # checkerboarding to occur
 default-preferences pref(layers.low-precision-buffer,false)
 skip-if(!asyncPan) == checkerboard-1.html checkerboard-1-ref.html

--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -1660,17 +1660,17 @@ fuzzy(1,68) fuzzy-if(gtkWidget,1,70) fai
 random-if(d2d) fails-if(Android) fuzzy-if(winWidget&&!d2d,20,118) fuzzy-if(skiaContent&&!Android,2,550) == 635373-2.html 635373-2-ref.html
 random-if(d2d) fails-if(Android) fuzzy-if(winWidget&&!d2d,20,116) fuzzy-if(skiaContent&&!Android,2,650) == 635373-3.html 635373-3-ref.html
 HTTP(..) == 635639-1.html 635639-1-ref.html
 HTTP(..) == 635639-2.html 635639-2-ref.html
 random == 637597-1.html 637597-1-ref.html # bug 637597 was never really fixed!
 fuzzy-if(Android,8,500) == 637852-1.html 637852-1-ref.html
 fuzzy-if(Android,8,500) fuzzy-if(skiaContent,2,1) fuzzy-if(webrender,3,19) == 637852-2.html 637852-2-ref.html
 fuzzy-if(Android,8,500) == 637852-3.html 637852-3-ref.html
-== 641770-1.html 641770-1-ref.html
+fails-if(webrender&&asyncPan) == 641770-1.html 641770-1-ref.html # bug 1374326 for webrender+APZ
 == 641856-1.html 641856-1-ref.html
 == 645491-1.html 645491-1-ref.html
 == 645647-1.html 645647-1-ref.html
 == 645647-2.html 645647-2-ref.html
 == 645768-1.html 645768-1-ref.html
 fails-if(layersGPUAccelerated&&cocoaWidget) fuzzy-if(!layersGPUAccelerated,41,260) fuzzy-if(skiaContent,57,11000) == 650228-1.html 650228-1-ref.html # Quartz alpha blending doesn't match GL alpha blending
 needs-focus == 652301-1a.html 652301-1-ref.html
 needs-focus == 652301-1b.html 652301-1-ref.html

--- a/layout/reftests/layers/reftest.list
+++ b/layout/reftests/layers/reftest.list
@@ -11,22 +11,26 @@ random-if(webrender) fuzzy-if(styloVsGec
 random-if(webrender) != pull-background-6.html about:blank
 
 # The animated-position tests are disabled for intermittent failures / passes, bug 1150941
 skip != pull-background-animated-position-1.html about:blank # Fails with event regions
 skip != pull-background-animated-position-2.html about:blank
 skip != pull-background-animated-position-3.html about:blank # Fails because PaintedLayer item assignment doesn't recognize overflow:hidden clips
 skip != pull-background-animated-position-4.html about:blank # Fails because PaintedLayer item assignment and background pulling don't recognize overflow:hidden clips
 skip != pull-background-animated-position-5.html about:blank # Fails because ownLayer bounds don't anticipate changes of animated contents, but doesn't fail with event regions
-skip-if(!asyncPan) != pull-background-displayport-1.html about:blank
-skip-if(!asyncPan) random-if(styloVsGecko) != pull-background-displayport-2.html about:blank
-skip-if(!asyncPan) != pull-background-displayport-3.html about:blank # fails with non-overlay scrollbars and event regions due to bug 1148515
-skip-if(!asyncPan) != pull-background-displayport-4.html about:blank # fails with non-overlay scrollbars and event regions due to bug 1148515
-skip-if(!asyncPan) fuzzy-if(styloVsGecko,1,1) != pull-background-displayport-5.html about:blank
-skip-if(!asyncPan) != pull-background-displayport-6.html about:blank # fails with non-overlay scrollbars and event regions due to bug 1148515
+
+# The pull-background-displayport-* tests are specific to "layers" and are not valid with webrender.
+# We mark them random-if to make sure they don't crash, but allow any result.
+random-if(webrender) skip-if(!asyncPan) != pull-background-displayport-1.html about:blank
+random-if(webrender) skip-if(!asyncPan) random-if(styloVsGecko) != pull-background-displayport-2.html about:blank
+random-if(webrender) skip-if(!asyncPan) != pull-background-displayport-3.html about:blank # fails with non-overlay scrollbars and event regions due to bug 1148515
+random-if(webrender) skip-if(!asyncPan) != pull-background-displayport-4.html about:blank # fails with non-overlay scrollbars and event regions due to bug 1148515
+random-if(webrender) skip-if(!asyncPan) fuzzy-if(styloVsGecko,1,1) != pull-background-displayport-5.html about:blank
+random-if(webrender) skip-if(!asyncPan) != pull-background-displayport-6.html about:blank # fails with non-overlay scrollbars and event regions due to bug 1148515
+
 fuzzy(2,30150) == opacity-blending.html opacity-blending-ref.html
 fuzzy(16,5) fails-if(webrender) == mask-layer-transform.html mask-layer-transform-ref.html
 fuzzy-if(gtkWidget,1,17) fuzzy-if(Android,3,4) == forced-bg-color-outside-visible-region.html forced-bg-color-outside-visible-region-ref.html
 != layerize-over-fixed-bg-1.html about:blank
 skip-if(!asyncPan) != fixed-pos-scrolled-clip-layerize.html about:blank
 skip-if(!asyncPan) == fixed-pos-scrolled-clip-opacity-layerize.html fixed-pos-scrolled-clip-opacity-inside-layerize.html
 
 # These tests check whether the GPU process is working. We expect it to work if:

--- a/layout/reftests/position-sticky/reftest.list
+++ b/layout/reftests/position-sticky/reftest.list
@@ -35,17 +35,17 @@ fuzzy-if(Android,2,3) == stacking-contex
 == left-right-3.html left-right-3-ref.html
 fuzzy-if(Android,4,810) == containing-block-1.html containing-block-1-ref.html
 == overconstrained-1.html overconstrained-1-ref.html
 == overconstrained-2.html overconstrained-2-ref.html
 == overconstrained-3.html overconstrained-3-ref.html
 == inline-1.html inline-1-ref.html
 == inline-2.html inline-2-ref.html
 fuzzy-if(OSX,99,210) == inline-3.html inline-3-ref.html
-skip-if(!asyncPan) == inline-4.html inline-4-ref.html
+fails-if(webrender) skip-if(!asyncPan) == inline-4.html inline-4-ref.html   # bug 1366295 for webrender
 fails-if(!styloVsGecko) == column-contain-1a.html column-contain-1-ref.html
 == column-contain-1b.html column-contain-1-ref.html
 == column-contain-2.html column-contain-2-ref.html
 == block-in-inline-1.html block-in-inline-1-ref.html
 fuzzy-if(skiaContent,1,22) fuzzy-if(winWidget&&!layersGPUAccelerated,116,1320) fuzzy-if(Android,8,1533) == block-in-inline-2.html block-in-inline-2-ref.html
 fuzzy-if(Android,8,630) fuzzy-if(OSX,1,11) fuzzy-if(skiaContent,1,220) fuzzy-if(winWidget&&!layersGPUAccelerated,116,1320) == block-in-inline-3.html block-in-inline-3-ref.html
 == block-in-inline-continuations.html block-in-inline-continuations-ref.html
 fuzzy-if(winWidget&&!layersGPUAccelerated,140,140) == inner-table-1.html inner-table-1-ref.html

--- a/widget/nsBaseWidget.cpp
+++ b/widget/nsBaseWidget.cpp
@@ -1252,20 +1252,16 @@ void nsBaseWidget::CreateCompositor(int 
   if (!mShutdownObserver) {
     return;
   }
 
   CreateCompositorVsyncDispatcher();
 
   bool enableWR = gfx::gfxVars::UseWebRender();
   bool enableAPZ = UseAPZ();
-  if (enableWR) {
-    // Disable APZ on widgets using WebRender, since it doesn't work yet.
-    enableAPZ = false;
-  }
   CompositorOptions options(enableAPZ, enableWR);
 
   RefPtr<LayerManager> lm;
   if (options.UseWebRender()) {
     lm = new WebRenderLayerManager(this);
   } else {
     lm = new ClientLayerManager(this);
   }