Revert "Suppress flaky canvas-teximage-after-multiple-drawimages.html test"

This reverts commit 953f1c19.

Reason for revert: Collided with https://chromium-review.googlesource.com/1338619

Original change's description:
> Suppress flaky canvas-teximage-after-multiple-drawimages.html test
> 
> The canvas-teximage-after-multiple-drawimages.html webgl test is flaky
> on MacOS and Android qualcomm. Add test suppression.
> 
> BUG=905682
> TBR=kbr@chromium.org
> 
> Change-Id: Id8fdb70f6dae6383c6d734916a3a724adbe00ea3
> Reviewed-on: https://chromium-review.googlesource.com/c/1338560
> Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
> Commit-Queue: Robert Kroeger <rjkroege@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#608605}

TBR=rjkroege@chromium.org,kbr@chromium.org

Change-Id: I863bac3201092184e47fbcd08acba8d1d83a2ffb
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 905682
Reviewed-on: https://chromium-review.googlesource.com/c/1338864Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608624}

content/test/gpu/gpu_tests/webgl_conformance_expectations.py

@@ -611,9 +611,7 @@ class WebGLConformanceExpectations(GpuTestExpectations):
         ['mac', ('intel', 0x0a2e)], bug=886970)
     self.Fail('conformance/rendering/rendering-stencil-large-viewport.html',
         ['mac', 'intel'], bug=782317)
-    self.Flaky('conformance/textures/misc/' +
-        'canvas-teximage-after-multiple-drawimages.html',
-        ['mac', 'intel'], bug=905682)
+
 
     # Mac Retina NVidia failures
     self.Fail('conformance/attribs/gl-disabled-vertex-attrib.html',
@@ -706,9 +704,6 @@ class WebGLConformanceExpectations(GpuTestExpectations):
     self.Skip('conformance/textures/misc/texture-npot-video.html',
         ['android', 'android-webview-instrumentation', 'no_passthrough'],
               bug=352645)
-    self.Flaky('conformance/textures/misc/' +
-        'canvas-teximage-after-multiple-drawimages.html',
-        ['android', 'qualcomm'], bug=905682)
 
     # These video tests appear to be flaky.
     self.Flaky('conformance/textures/video/' +