aw: Enable OffscreenCanvas tests

This CL re-enables OffscreenCanvas tests that depedends on surface
embedding as VizForWebView is enabled in fieldtrial_testing_config.json
for a while now.
Tests pass on gpu-fyi-try-android-m-nexus-5x-64 bot.

Bug: 805739
Change-Id: I2dbb32e684005fe9521d91289d2d5c992a261394
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2088339Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Vasiliy Telezhnikov <vasilyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747463}

content/test/gpu/gpu_tests/test_expectations/pixel_expectations.txt

@@ -53,22 +53,6 @@ crbug.com/653538 [ win amd-0x6613 ] Pixel_GpuRasterization_BlueBox [ RetryOnFail
 [ android ] Pixel_CSS3DBlueBox_NoGpuProcess [ Skip ]
 [ chromeos ] Pixel_CSS3DBlueBox_NoGpuProcess [ Skip ]
 
-# Skip tests on Android WebView that requires embedding viz clients. This
-# includes offscreen canvas and other features. crbug.com/805739 tracks
-# making this work.
-crbug.com/805739 [ android android-webview-instrumentation ] Pixel_OffscreenCanvas2DResizeOnWorker [ Skip ]
-crbug.com/805739 [ android-webview-instrumentation ] Pixel_OffscreenCanvasAccelerated2D [ Skip ]
-crbug.com/805739 [ android-webview-instrumentation ] Pixel_OffscreenCanvasAccelerated2DWorker [ Skip ]
-crbug.com/805739 [ android-webview-instrumentation ] Pixel_OffscreenCanvasTransferAfterStyleResize [ Skip ]
-crbug.com/805739 [ android android-webview-instrumentation ] Pixel_OffscreenCanvasTransferBeforeStyleResize [ Skip ]
-crbug.com/805739 [ android-webview-instrumentation ] Pixel_OffscreenCanvasWebGLDefault [ Skip ]
-crbug.com/805739 [ android-webview-instrumentation ] Pixel_OffscreenCanvasWebGLDefaultWorker [ Skip ]
-crbug.com/805739 [ android-webview-instrumentation ] Pixel_OffscreenCanvasWebGLPaintAfterResize [ Skip ]
-crbug.com/805739 [ android android-webview-instrumentation ] Pixel_OffscreenCanvasWebglResizeOnWorker [ Skip ]
-crbug.com/805739 [ android android-webview-instrumentation ] Pixel_CanvasLowLatencyWebGL [ Skip ]
-crbug.com/992599 [ android android-webview-instrumentation ] Pixel_OffscreenCanvasTransferToImageBitmapWorker [ Skip ]
-crbug.com/992599 [ android android-webview-instrumentation ] Pixel_OffscreenCanvasTransferToImageBitmap [ Skip ]
-
 # Fails on Android WebView due to requiring embedding viz clients. crbug.com/805739
 # Produces black images on Nexus 5Xs in Android Webview (qualcomm-adreno-(tm)-418) crbug.com/984352
 # Fails on Pixel 2 (qualcomm-adreno-(tm)-540) crbug.com/966069