Stop exposing --disable-gpu-compositing as a Blink RuntimeEnabledFeature

content/renderer/renderer_blink_platform_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_RENDERER_BLINK_PLATFORM_IMPL_H_
 #define CONTENT_RENDERER_RENDERER_BLINK_PLATFORM_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 124 matching lines @@
   blink::WebScrollbarBehavior* scrollbarBehavior() override;
   blink::WebIDBFactory* idbFactory() override;
   blink::WebServiceWorkerCacheStorage* cacheStorage(
       const blink::WebSecurityOrigin& security_origin) override;
   blink::WebFileSystem* fileSystem() override;
   blink::WebString fileSystemCreateOriginIdentifier(
       const blink::WebSecurityOrigin& origin) override;
 
   bool isThreadedCompositingEnabled() override;
   bool isThreadedAnimationEnabled() override;
+  bool isGPUCompositingEnabled() override;
   double audioHardwareSampleRate() override;
   size_t audioHardwareBufferSize() override;
   unsigned audioHardwareOutputChannels() override;
   blink::WebDatabaseObserver* databaseObserver() override;
 
   blink::WebAudioDevice* createAudioDevice(
       size_t buffer_size,
       unsigned input_channels,
       unsigned channels,
       double sample_rate,
@@ skipping 156 matching lines @@
   std::unique_ptr<BlinkInterfaceProviderImpl> blink_interface_provider_;
 
   mojom::URLLoaderFactoryPtr url_loader_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererBlinkPlatformImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDERER_BLINK_PLATFORM_IMPL_H_