--- a/dom/canvas/test/webgl-conf/generated-mochitest.ini
+++ b/dom/canvas/test/webgl-conf/generated-mochitest.ini
@@ -6209,16 +6209,17 @@ skip-if = (os == 'android' || os == 'lin
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__extensions__webgl-compressed-texture-pvrtc.html]
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__extensions__webgl-compressed-texture-s3tc-srgb.html]
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__extensions__webgl-compressed-texture-s3tc.html]
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__extensions__webgl-compressed-texture-size-limit.html]
+fail-if = (os == 'win' && os_version == '6.1' && debug && !e10s)
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__extensions__webgl-debug-renderer-info.html]
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__extensions__webgl-debug-shaders.html]
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__extensions__webgl-shared-resources.html]
 skip-if = (os == 'android' || os == 'linux')
 [generated/test_2_conformance__glsl__bugs__angle-ambiguous-function-call.html]
@@ -7602,16 +7603,17 @@ fail-if = (os == 'mac') || (os == 'win')
 skip-if = (os == 'mac' && os_version == '10.6')
 fail-if = (os == 'mac') || (os == 'linux') || (os == 'win')
 [generated/test_conformance__extensions__webgl-compressed-texture-atc.html]
 [generated/test_conformance__extensions__webgl-compressed-texture-etc.html]
 [generated/test_conformance__extensions__webgl-compressed-texture-pvrtc.html]
 [generated/test_conformance__extensions__webgl-compressed-texture-s3tc-srgb.html]
 [generated/test_conformance__extensions__webgl-compressed-texture-s3tc.html]
 [generated/test_conformance__extensions__webgl-compressed-texture-size-limit.html]
+skip-if = (os == 'win' && os_version == '6.1')
 [generated/test_conformance__extensions__webgl-debug-renderer-info.html]
 [generated/test_conformance__extensions__webgl-debug-shaders.html]
 [generated/test_conformance__extensions__webgl-depth-texture.html]
 [generated/test_conformance__extensions__webgl-draw-buffers-framebuffer-unsupported.html]
 [generated/test_conformance__extensions__webgl-draw-buffers-max-draw-buffers.html]
 [generated/test_conformance__extensions__webgl-draw-buffers.html]
 skip-if = (os == 'linux')
 fail-if = (os == 'win')

--- a/dom/canvas/test/webgl-conf/mochitest-errata.ini
+++ b/dom/canvas/test/webgl-conf/mochitest-errata.ini
@@ -858,16 +858,19 @@ skip-if = (os == 'win')
 # Crashes on D3D11 debug.
 skip-if = (os == 'win')
 [generated/test_2_conformance2__glsl3__uniform-location-length-limits.html]
 # time out crash
 skip-if = (os == 'win' && debug)
 [generated/test_conformance__textures__misc__tex-image-and-sub-image-2d-with-array-buffer-view.html]
 # time out crash
 skip-if = (os == 'win' && debug)
+[generated/test_conformance__extensions__webgl-compressed-texture-size-limit.html]
+# timeout on win7.
+skip-if = (os == 'win' && os_version == '6.1')
 [generated/test_2_conformance2__glsl3__loops-with-side-effects.html]
 # application crashed [@ nvoglv32.dll + 0x999512]
 skip-if = (os == 'win')
 [generated/test_2_conformance2__attribs__gl-vertex-attrib-i-render.html]
 # timed out crash
 skip-if = (os == 'win')
 [generated/test_2_conformance__canvas__canvas-test.html]
 # this test is not always passed every time on opt and debug build
@@ -928,12 +931,15 @@ skip-if = (os == 'win' && os_version == 
 # Failure on win7 but got passed on win7 vm
 skip-if = (os == 'win' && os_version == '6.1')
 [generated/test_2_conformance__glsl__constructors__glsl-construct-vec4.html]
 # Failure on win7 but got passed on win7 vm
 skip-if = (os == 'win' && os_version == '6.1')
 [generated/test_2_conformance__textures__misc__tex-image-and-sub-image-2d-with-array-buffer-view.html]
 # Failure on win7 but got passed on win7 vm
 skip-if = (os == 'win' && os_version == '6.1')
+[generated/test_2_conformance__extensions__webgl-compressed-texture-size-limit.html]
+# timeout on win7 debug no e10s.
+fail-if = (os == 'win' && os_version == '6.1' && debug && !e10s)
 [generated/test_2_conformance2__textures__misc__tex-input-validation.html]
 skip-if = (os == 'win')
 [generated/test_2_conformance2__buffers__get-buffer-sub-data.html]
 skip-if = (os == 'win')