Remove failure entries in gpu pixel test

content/test/gpu/gpu_tests/pixel_expectations.py

Index: content/test/gpu/gpu_tests/pixel_expectations.py
diff --git a/content/test/gpu/gpu_tests/pixel_expectations.py b/content/test/gpu/gpu_tests/pixel_expectations.py
index 765f41039cac795011ce645c06fc9f9acff3a09b..0f7c774dd65ed57d9928f2a76dbf66b3491baac2 100644
--- a/content/test/gpu/gpu_tests/pixel_expectations.py
+++ b/content/test/gpu/gpu_tests/pixel_expectations.py
@@ -34,8 +34,8 @@ class PixelExpectations(GpuTestExpectations):
     # TODO(xlai) check / generate reference images.
     self.Fail('Pixel_OffscreenCanvasUnaccelerated2D', bug=563852)
     self.Fail('Pixel_OffscreenCanvasUnaccelerated2DWorker', bug=563858)
-    self.Fail('Pixel_OffscreenCanvasUnaccelerated2DGPUCompositing', bug=563852)
-    self.Fail('Pixel_OffscreenCanvasUnaccelerated2DGPUCompositingWorker', bug=563858)
+    self.Fail('Pixel_OffscreenCanvasUnaccelerated2DGPUCompositingWorker',
+              ['mac', ('nvidia', 0xfe9)], bug=652931)
 
     # TODO(kbr): flakily timing out on this configuration.
     self.Flaky('*', ['linux', 'intel', 'debug'], bug=648369)