Adding test to verify that Canvas2DLayerBridge flushes only when required

third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.h

 /*
  * Copyright (C) 2012 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 126 matching lines @@
   void dontUseIdleSchedulingForTesting() {
     m_dontUseIdleSchedulingForTesting = true;
   }
 
   void beginDestruction();
   void hibernate();
   bool isHibernating() const { return m_hibernationImage.get(); }
   sk_sp<SkColorSpace> colorSpace() const { return m_colorSpace; }
   SkColorType colorType() const { return m_colorType; }
 
+  bool hasRecordedDrawCommands() { return m_haveRecordedDrawCommands; }
+
   sk_sp<SkImage> newImageSnapshot(AccelerationHint, SnapshotReason);
 
   // The values of the enum entries must not change because they are used for
   // usage metrics histograms. New values can be added to the end.
   enum HibernationEvent {
     HibernationScheduled = 0,
     HibernationAbortedDueToDestructionWhileHibernatePending = 1,
     HibernationAbortedDueToPendingDestruction = 2,
     HibernationAbortedDueToVisibilityChange = 3,
     HibernationAbortedDueGpuContextLoss = 4,
@@ skipping 138 matching lines @@
   // Each element in this vector represents an IOSurface backed texture that
   // is ready to be reused.
   // Elements in this vector can safely be purged in low memory conditions.
   Vector<RefPtr<ImageInfo>> m_imageInfoCache;
 #endif  // USE_IOSURFACE_FOR_2D_CANVAS
 };
 
 }  // namespace blink
 
 #endif