Reenable Pixel_CanvasLowLatency2D test

crrev.com/c/1294870 uprev'ed Pixel_CanvasLowLatency2D, this CL now
reenables it.  To monitor: android-marshmallow-arm64-rel bot.

Bug: 865957
Change-Id: I89eb31722c430b0134093a7d9db51ae469b76652
Reviewed-on: https://chromium-review.googlesource.com/c/1306648Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604659}

content/test/gpu/gpu_tests/pixel_expectations.py

@@ -45,9 +45,6 @@ class PixelExpectations(GpuTestExpectations):
     self.Fail('Pixel_ScissorTestWithPreserveDrawingBuffer',
         ['android'], bug=521588)
 
-    # TODO(mcasas): Reenable after Android reference images are updated
-    self.Fail('Pixel_CanvasLowLatency2D', bug=865957)
-
     # TODO(vmiura) check / generate reference images for Android devices
     self.Fail('Pixel_SolidColorBackground', ['mac', 'android'], bug=624256)