Allow DrawingBuffer to present to a bitmap.

public/platform/WebExternalBitmap.h

 /*
  * Copyright (C) 2013 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 10 matching lines @@
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WebGraphicsContext3DProvider_h
-#define WebGraphicsContext3DProvider_h
-
-#include "WebCommon.h"
-
-class GrContext;
+#ifndef WebExternalBitmap_h
+#define WebExternalBitmap_h
 
 namespace WebKit {
-class WebGraphicsContext3D;
 
-class WebGraphicsContext3DProvider {
+struct WebSize;

[jamesr, 2013/07/03 21:53:02]

since you're returning WebSize by value, i think you need to #include the header
that defines it since anyone who uses this header will need to see the
definition of WebSize anyway

+
+class WebExternalBitmap {
 public:
-    virtual ~WebGraphicsContext3DProvider() { }
+    virtual WebSize getSize() = 0;

[jamesr, 2013/07/03 21:53:02]

no 'get' prefix needed for this. just size().

 
-    virtual WebGraphicsContext3D* context3d() = 0;
-    virtual GrContext* grContext() = 0;
+    // Sets the size of the bitmap. This may reallocate the bitmap and
+    // invalidate the pointer returned from getPointer if the size changes.
+    virtual void setSize(WebSize) = 0;
+
+    virtual void* getPointer() = 0;

[jamesr, 2013/07/03 21:53:02]

what is the type of this? is it a pointer into the pixel buffer? that should
probably be uint8* or something similar.

we very very rarely use the 'get' prefix in blink code. i think this should be
named after what it points to

 };
 
 } // namespace WebKit
 
-#endif
+#endif // WebExternalBitmap_h