Improve Fullscreen unit tests

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

 // Copyright 2013 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 WebLayerTreeViewImplForTesting_h
 #define WebLayerTreeViewImplForTesting_h
 
 #include "cc/test/test_task_graph_runner.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_single_thread_client.h"
@@ skipping 18 matching lines @@
   WTF_MAKE_NONCOPYABLE(WebLayerTreeViewImplForTesting);
 
  public:
   WebLayerTreeViewImplForTesting();
   explicit WebLayerTreeViewImplForTesting(const cc::LayerTreeSettings&);
   ~WebLayerTreeViewImplForTesting() override;
 
   static cc::LayerTreeSettings defaultLayerTreeSettings();
   cc::LayerTreeHost* layerTreeHost() { return m_layerTreeHost.get(); }
   bool hasLayer(const WebLayer&);
+  bool hasTransparentBackground();
 
   // blink::WebLayerTreeView implementation.
   void setRootLayer(const blink::WebLayer&) override;
   void clearRootLayer() override;
   void attachCompositorAnimationTimeline(cc::AnimationTimeline*) override;
   void detachCompositorAnimationTimeline(cc::AnimationTimeline*) override;
   virtual void setViewportSize(const blink::WebSize& unusedDeprecated,
                                const blink::WebSize& deviceViewportSize);
   void setViewportSize(const blink::WebSize&) override;
   WebSize getViewportSize() const override;
@@ skipping 53 matching lines @@
 
  private:
   cc::TestTaskGraphRunner m_taskGraphRunner;
   std::unique_ptr<cc::AnimationHost> m_animationHost;
   std::unique_ptr<cc::LayerTreeHost> m_layerTreeHost;
 };
 
 }  // namespace blink
 
 #endif  // WebLayerTreeViewImplForTesting_h