Use std::unique_ptr to signal ownership transfer in WebCompositorSupport

third_party/WebKit/Source/platform/testing/TestingPlatformSupport.h

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 44 matching lines @@
 namespace blink {
 namespace scheduler {
 class RendererScheduler;
 class RendererSchedulerImpl;
 }
 class TestingPlatformMockWebTaskRunner;
 class TestingPlatformMockWebThread;
 class WebCompositorSupport;
 class WebThread;
 
-class TestingCompositorSupport : public WebCompositorSupport {};
+class TestingCompositorSupport : public WebCompositorSupport {
+  std::unique_ptr<WebLayer> createLayer() override;
+  std::unique_ptr<WebLayer> createLayerFromCCLayer(cc::Layer*) override;
+  std::unique_ptr<WebContentLayer> createContentLayer(
+      WebContentLayerClient*) override;
+  std::unique_ptr<WebExternalTextureLayer> createExternalTextureLayer(
+      cc::TextureLayerClient*) override;
+  std::unique_ptr<WebImageLayer> createImageLayer() override;
+  std::unique_ptr<WebScrollbarLayer> createScrollbarLayer(
+      std::unique_ptr<WebScrollbar>,
+      WebScrollbarThemePainter,
+      std::unique_ptr<WebScrollbarThemeGeometry>) override;
+  std::unique_ptr<WebScrollbarLayer> createSolidColorScrollbarLayer(
+      WebScrollbar::Orientation,
+      int thumbThickness,
+      int trackStart,
+      bool isLeftSideVerticalScrollbar) override;
+};
 
 class TestingPlatformMockScheduler : public WebScheduler {
   WTF_MAKE_NONCOPYABLE(TestingPlatformMockScheduler);
 
  public:
   TestingPlatformMockScheduler();
   ~TestingPlatformMockScheduler() override;
 
   void runSingleTask();
   void runAllTasks();
@@ skipping 113 matching lines @@
       m_discardableMemoryAllocator;
   std::unique_ptr<DummyPlatform> m_platform;
   std::unique_ptr<cc_blink::WebCompositorSupportImpl> m_compositorSupport;
   TestingPlatformSupport::Config m_testingPlatformConfig;
   std::unique_ptr<TestingPlatformSupport> m_testingPlatformSupport;
 };
 
 }  // namespace blink
 
 #endif  // TestingPlatformSupport_h