--- a/layout/reftests/transform-3d/reftest.list
+++ b/layout/reftests/transform-3d/reftest.list
@@ -1,92 +1,100 @@
+# this pref is only meaningful if webrender is enabled. it is reset by the
+# default-preferences line at the end of the file, and so only affects the
+# tests in this folder.
+default-preferences pref(gfx.webrender.layers-free,true)
+
 == scalez-1a.html scalez-1-ref.html
 == rotatey-1a.html rotatey-1-ref.html
 == rotatex-1a.html rotatex-1-ref.html
 # Check that scaleZ(-1) rotateX(180deg) is the same as rotateY(180deg)
 == scalezrotatex-1.html scalezrotatex-1-ref.html
 # Check that the perspectve() transform function results in some visual changes
 != rotatex-perspective-1a.html rotatex-1-ref.html
 # Check that -moz-perspective results in visual changes to child transformed elements
 != rotatex-perspective-1b.html rotatex-1-ref.html
 # -moz-perspective should only apply to child elements
 == rotatex-perspective-1c.html rotatex-1-ref.html
 == rotatex-perspective-3a.html rotatex-perspective-3-ref.html
 == scalez-1a.html scalez-1-ref.html
-fuzzy-if(gtkWidget||winWidget,8,376) fuzzy-if(Android,8,441) fuzzy-if(cocoaWidget,17,4) fuzzy-if(skiaContent,16,286) fails-if(webrender) == preserve3d-1a.html preserve3d-1-ref.html
+fuzzy-if(gtkWidget||winWidget,8,376) fuzzy-if(Android,8,441) fuzzy-if(cocoaWidget,17,4) fuzzy-if(skiaContent,16,286) == preserve3d-1a.html preserve3d-1-ref.html
 == preserve3d-1b.html about:blank
 == preserve3d-clipped.html about:blank
-fails-if(webrender) == preserve3d-2a.html preserve3d-2-ref.html
-fails-if(webrender) == preserve3d-2b.html preserve3d-2-ref.html
+== preserve3d-2a.html preserve3d-2-ref.html
+== preserve3d-2b.html preserve3d-2-ref.html
 == preserve3d-2c.html preserve3d-2-ref.html
-fails-if(webrender) == preserve3d-2d.html preserve3d-2-ref.html
-fails-if(webrender) == preserve3d-3a.html preserve3d-3-ref.html
+== preserve3d-2d.html preserve3d-2-ref.html
+== preserve3d-3a.html preserve3d-3-ref.html
 == preserve3d-4a.html about:blank
-fuzzy-if(gtkWidget,4,200) fuzzy-if(Android,4,300) fuzzy-if(winWidget&&!layersGPUAccelerated,2,100) fuzzy-if(skiaContent,16,100) fails-if(webrender) == preserve3d-5a.html preserve3d-5-ref.html
+fuzzy-if(gtkWidget,4,200) fuzzy-if(Android,4,300) fuzzy-if(winWidget&&!layersGPUAccelerated,2,100) fuzzy-if(skiaContent,16,100) == preserve3d-5a.html preserve3d-5-ref.html
 == preserve3d-6a.html preserve3d-6-ref.html
 == scale3d-z.html scalez-1-ref.html
 fuzzy-if(winWidget,143,689) fuzzy-if(OSX,224,924) fuzzy-if(winWidget&&stylo,154,644) == scale3d-all.html scale3d-1-ref.html # subpixel AA
 fuzzy-if(winWidget,143,689) fuzzy-if(OSX,224,924) fuzzy-if(winWidget&&stylo,154,644) == scale3d-all-separate.html scale3d-1-ref.html # subpixel AA
 == scale3d-xz.html scale3d-1-ref.html
 == translatez-1a.html translatez-1-ref.html
 != translatez-1b.html translatez-1-ref.html
 == translate3d-1a.html translate3d-1-ref.html
 fuzzy-if(skiaContent,1,4) == matrix3d-1a.html matrix3d-1-ref.html
 == matrix3d-2a.html matrix3d-2-ref.html
 == rotate3d-1a.html rotatex-1-ref.html
 == rotate3d-2a.html rotatey-1-ref.html
 != backface-visibility-1a.html about:blank
-== backface-visibility-1b.html about:blank
-== backface-visibility-1c.html about:blank
-fuzzy-if(winWidget&&!layersGPUAccelerated,1,251) == backface-visibility-2.html backface-visibility-2-ref.html
-fails-if(webrender) == backface-visibility-3.html backface-visibility-3-ref.html
-== perspective-clipping-1.html perspective-clipping-1-ref.html
+fails-if(webrender) == backface-visibility-1b.html about:blank
+fails-if(webrender) == backface-visibility-1c.html about:blank
+fuzzy-if(winWidget&&!layersGPUAccelerated,1,251) fails-if(webrender) == backface-visibility-2.html backface-visibility-2-ref.html
+== backface-visibility-3.html backface-visibility-3-ref.html
+fails-if(webrender) == perspective-clipping-1.html perspective-clipping-1-ref.html
 == perspective-clipping-2.html perspective-clipping-2-ref.html
 != perspective-origin-1a.html rotatex-perspective-1a.html
 == perspective-origin-1b.html perspective-origin-1a.html
 fuzzy(3,99) random-if(Android&&!browserIsRemote) == perspective-origin-2a.html perspective-origin-2-ref.html # subpixel AA, bug 732568
 fuzzy-if(winWidget&&!layersGPUAccelerated,1,61) == perspective-origin-3a.html perspective-origin-3-ref.html
 == perspective-origin-4a.html perspective-origin-4-ref.html
-fails-if(webrender) == perspective-zindex.html green-rect.html
-fails-if(webrender) == perspective-zindex-2.html green-rect.html
+== perspective-zindex.html green-rect.html
+== perspective-zindex-2.html green-rect.html
 fails-if(webrender) != sorting-1a.html sorting-1-ref.html
 # Parallel planes, different z depth
 fails-if(webrender) == sorting-2a.html sorting-2-ref.html
 # Parallel planes, same z depth (shouldn't be sorted!)
-fails-if(webrender) == sorting-2b.html sorting-2-ref.html
-fails-if(webrender) == sorting-3a.html green-rect.html
+== sorting-2b.html sorting-2-ref.html
+== sorting-3a.html green-rect.html
 # Different, but equivalent (for the given transform) transform origins
 == rotatex-transformorigin-1a.html rotatex-transformorigin-1-ref.html
 fuzzy-if((gtkWidget&&layersOMTC)||(winWidget&&!layersGPUAccelerated),1,86) == overflow-hidden-1a.html overflow-hidden-1-ref.html
 fails-if(webrender) == transform-style-flat-1a.html transform-style-flat-1-ref.html
 == willchange-containing-block.html?willchange willchange-containing-block.html?ref
 != willchange-containing-block.html?willchange willchange-containing-block.html?noblock
 fuzzy-if(winWidget&&!layersGPUAccelerated,1,606) == scroll-perspective-1.html scroll-perspective-1-ref.html
 # Bugs
 fails-if(!layersGPUAccelerated) fails-if(webrender) == 1035611-1.html 1035611-1-ref.html # Bug 1072898 for !layersGPUAccelerated failures
-!= 1157984-1.html about:blank # Bug 1157984
+fails-if(webrender) != 1157984-1.html about:blank # Bug 1157984
 fuzzy(3,99) == animate-cube-radians.html animate-cube-radians-ref.html # subpixel AA
 fuzzy(3,99) fuzzy-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)&&!layersGPUAccelerated,16,6) == animate-cube-radians-zoom.html animate-cube-radians-zoom-ref.html
 != animate-cube-radians-ref.html animate-cube-radians-zoom-ref.html
 fuzzy(3,99) == animate-cube-degrees.html animate-cube-degrees-ref.html # subpixel AA
 == animate-cube-degrees-zoom.html animate-cube-degrees-zoom-ref.html
 != animate-cube-degrees-ref.html animate-cube-degrees-zoom-ref.html
-fuzzy-if(gtkWidget,128,100) fuzzy-if(Android||OSX==1010||(gtkWidget&&layersGPUAccelerated),143,100) fuzzy-if(winWidget||OSX<1010,141,100) fails-if(webrender) == preserves3d-nested.html preserves3d-nested-ref.html
+fuzzy-if(gtkWidget,128,100) fuzzy-if(Android||OSX==1010||(gtkWidget&&layersGPUAccelerated),143,100) fuzzy-if(winWidget||OSX<1010,141,100) == preserves3d-nested.html preserves3d-nested-ref.html
 fuzzy-if(cocoaWidget,128,9) == animate-preserve3d-parent.html animate-preserve3d-ref.html # intermittently fuzzy on Mac
 fuzzy-if(cocoaWidget,128,9) == animate-preserve3d-child.html animate-preserve3d-ref.html # intermittently fuzzy on Mac
-== animate-backface-hidden.html about:blank
-fails-if(webrender) == 1245450-1.html green-rect.html
+fails-if(webrender) == animate-backface-hidden.html about:blank
+== 1245450-1.html green-rect.html
 fuzzy(1,2000) == opacity-preserve3d-1.html opacity-preserve3d-1-ref.html
 fuzzy(1,15000) == opacity-preserve3d-2.html opacity-preserve3d-2-ref.html
 fuzzy(1,10000) == opacity-preserve3d-3.html opacity-preserve3d-3-ref.html
 fuzzy(1,10000) == opacity-preserve3d-4.html opacity-preserve3d-4-ref.html
 == opacity-preserve3d-5.html opacity-preserve3d-5-ref.html
 fails-if(webrender) == snap-perspective-1.html snap-perspective-1-ref.html
-fails-if(webrender) == mask-layer-1.html mask-layer-ref.html
+== mask-layer-1.html mask-layer-ref.html
 fails-if(webrender) == mask-layer-2.html mask-layer-ref.html
 fails-if(webrender) == mask-layer-3.html mask-layer-ref.html
 fails-if(webrender) == split-intersect1.html split-intersect1-ref.html
 fuzzy(255,150) fails-if(webrender) == split-intersect2.html split-intersect2-ref.html
 fuzzy(255,100) fails-if(webrender) == split-non-ortho1.html split-non-ortho1-ref.html
-fuzzy-if(winWidget,150,120) fails-if(webrender) == component-alpha-1.html component-alpha-1-ref.html
-fails-if(webrender) == nested-transform-1.html nested-transform-1-ref.html
-fails-if(webrender) == transform-geometry-1.html transform-geometry-1-ref.html
-fails-if(webrender) == intermediate-1.html intermediate-1-ref.html
+fuzzy-if(winWidget,150,120) == component-alpha-1.html component-alpha-1-ref.html
+== nested-transform-1.html nested-transform-1-ref.html
+== transform-geometry-1.html transform-geometry-1-ref.html
+== intermediate-1.html intermediate-1-ref.html
+
+# reset gfx.webrender.layers-free,true
+default-preferences

--- a/layout/reftests/transform/reftest.list
+++ b/layout/reftests/transform/reftest.list
@@ -1,8 +1,13 @@
+# this pref is only meaningful if webrender is enabled. it is reset by the
+# default-preferences line at the end of the file, and so only affects the
+# tests in this folder.
+default-preferences pref(gfx.webrender.layers-free,true)
+
 # Transforms specifying singular matrices shouldn't display at all.
 # NOTE: Regressions might manifest themselves as reftest timeouts on
 # this test.
 == singular-1a.html about:blank
 # Multiple transforms should act identically to nested divs.
 fuzzy-if(webrender,1,27) == compound-1a.html compound-1-ref.html
 != compound-1a.html compound-1-fail.html
 == dynamic-inherit-1.html dynamic-inherit-1-ref.html
@@ -26,33 +31,31 @@ fuzzy-if(webrender,1,27) == compound-1a.
 # matrices defined to be translations should act like position: relative
 == translatex-2.html translatex-1-ref.html
 == translatey-2.html translatey-1-ref.html
 # translate should act like position: relative
 != translate-1a.html translate-1-ref.html
 == translate-1b.html translate-1-ref.html
 == translate-1c.html translate-1-ref.html
 == translate-1d.html translate-1-ref.html
-pref(gfx.webrender.layers-free,true) skip-if(!webrender) == translate-1d.html translate-1-ref.html
 == translate-1e.html translate-1-ref.html
 == translate-2a.html translate-2-ref.html
 == translate-3.html translate-3-ref.html
 # rotate: Several rotations of the same object should be idempotent.  These
 # tests are currently disabled because of subpixel (< 0.00001 gfx units)
 # rounding errors.
 random == rotate-1a.html rotate-1-ref.html
 random == rotate-1b.html rotate-1-ref.html
 random == rotate-1c.html rotate-1-ref.html
 random == rotate-1d.html rotate-1-ref.html
 random == rotate-1e.html rotate-1-ref.html
 random == rotate-1f.html rotate-1-ref.html
 # rotate: 90deg rotations should be indistinguishable from objects constructed
 # to look the same.
 == rotate-2a.html rotate-2-ref.html
-pref(gfx.webrender.layers-free,true) skip-if(!webrender) == rotate-2a.html rotate-2-ref.html
 == rotate-2b.html rotate-2-ref.html
 # -transform-origin: We should NOT get the same images when using different
 # -transform-origins.
 != origin-1a.html origin-1-ref.html
 != origin-1b.html origin-1-ref.html
 # -transform-origin: We should get the same images when using equivalent
 # -transform-origins.
 == origin-2a.html origin-2-ref.html
@@ -144,8 +147,11 @@ pref(svg.transform-box.enabled,true) == 
 # Bug 1301500
 == dynamic-add-without-change-cb-1.html dynamic-add-without-change-cb-1-ref.html
 fuzzy-if(d2d,1,5) fuzzy-if(skiaContent,22,180) == table-overflowed-by-animation.html table-overflowed-by-animation-ref.html
 # Bug 1392161. These tests are failed on Gecko (Bug 1396535). The viewport
 # length transform test is also failed on Servo backend.
 fails-if(!stylo) == translate-rounding-1.html translate-rounding-ref.html
 fails-if(!stylo) == translate-rounding-2.html translate-rounding-ref.html
 fails == translate-rounding-3.html translate-rounding-viewport-ref.html
+
+# reset gfx.webrender.layers-free,true
+default-preferences