Reland: Make 2D canvas disable gpu acceleration when getImageData is called

third_party/WebKit/Source/platform/blink_platform.gypi

 {
   'includes': [
     'platform_generated.gypi',
   ],
   'variables': {
     'platform_files': [
       'AsyncFileSystemCallbacks.h',
       'CalculationValue.h',
       'CheckedInt.h',
       'ContentDecryptionModuleResult.h',
@@ skipping 1261 matching lines @@
     # These tests are a part of the web:webkit_unit_tests binary.
     'platform_web_unittest_files': [
       'graphics/Canvas2DLayerBridgeTest.cpp',
       'graphics/CanvasSurfaceLayerBridgeTest.cpp',
       'graphics/DeferredImageDecoderTest.cpp',
       'graphics/GraphicsLayerTest.cpp',
       'graphics/ImageDecodingStoreTest.cpp',
       'graphics/ImageFrameGeneratorTest.cpp',
       'graphics/ImageLayerChromiumTest.cpp',
       'graphics/test/FakeGLES2Interface.h',
+      'graphics/test/FakeWebGraphicsContext3DProvider.h',
       'graphics/test/MockImageDecoder.h',
     ],
     'platform_test_support_files': [
       'scroll/ScrollbarTestSuite.h',
       'testing/CompositorTest.cpp',
       'testing/CompositorTest.h',
       'testing/FakeDisplayItemClient.h',
       'testing/FakeGraphicsLayer.h',
       'testing/FakeGraphicsLayerClient.h',
       'testing/FontTestHelpers.cpp',
@@ skipping 57 matching lines @@
       ['use_default_render_theme==1',
         {
           'platform_test_files': [
             'scroll/ScrollbarThemeAuraTest.cpp',
           ],
         }
       ],
     ],
   },
 }