Allow explicit conversion operators and implement WTF::OwnPtr::operator bool.

third_party/WebKit/Source/core/html/HTMLCanvasElement.h

 /*
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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.
@@ skipping 121 matching lines @@
 
     SecurityOrigin* getSecurityOrigin() const;
     bool originClean() const;
     void setOriginTainted() { m_originClean = false; }
 
     AffineTransform baseTransform() const;
 
     bool is3D() const;
     bool isAnimated2D() const;
 
-    bool hasImageBuffer() const { return m_imageBuffer; }
+    bool hasImageBuffer() const { return m_imageBuffer.get(); }
     void discardImageBuffer();
 
     bool shouldAccelerate(const IntSize&) const;
 
     bool shouldBeDirectComposited() const;
 
     void prepareSurfaceForPaintingIfNeeded() const;
 
     const AtomicString imageSourceURL() const override;
 
@@ skipping 83 matching lines @@
     mutable bool m_didFailToCreateImageBuffer;
     bool m_imageBufferIsClear;
     OwnPtr<ImageBuffer> m_imageBuffer;
 
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
 };
 
 } // namespace blink
 
 #endif // HTMLCanvasElement_h