Remove supressions for rebaselined gpu pixel tests

Affected tests:
Pixel_OffscreenCanvasTransferToImageBitmap
Pixel_OffscreenCanvasTransferToImageBitmapWorker

BUG=696224, 585607
TBR=xlai@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2804323002
Cr-Commit-Position: refs/heads/master@{#462991}

content/test/gpu/gpu_tests/pixel_expectations.py

@@ -28,12 +28,6 @@ class PixelExpectations(GpuTestExpectations):
     self.Fail('Pixel_ScissorTestWithPreserveDrawingBuffer',
         ['android'], bug=521588)
 
-    # TODO(junov) needs new baseline
-    self.Fail('Pixel_OffscreenCanvasTransferToImageBitmap',
-        bug=585607)
-    self.Fail('Pixel_OffscreenCanvasTransferToImageBitmapWorker',
-        bug=585607)
-
     # TODO(ccameron) fix these on Mac Retina
     self.Fail('Pixel_CSS3DBlueBox', ['mac'], bug=533690)