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 WebDOMResourceProgressEvent_h
-#define WebDOMResourceProgressEvent_h
+#ifndef WebExternalBitmap_h
+#define WebExternalBitmap_h
 
-#include "WebDOMProgressEvent.h"
+#include "WebSize.h"
 
 namespace WebKit {
 
-class WebString;
+class WebExternalBitmap {
+public:
+    virtual WebSize size() = 0;
 
-class WebDOMResourceProgressEvent : public WebDOMProgressEvent {
-public:
-    WebDOMResourceProgressEvent() { }
-    WEBKIT_EXPORT WebDOMResourceProgressEvent(const WebString& type, bool lengthIsComputable, unsigned long long loaded, unsigned long long total, const WebString& url);
+    // Sets the size of the bitmap. This may reallocate the bitmap and
+    // invalidate the pointer returned from pixels if the size changes.
+    virtual void setSize(WebSize) = 0;
+
+    // Returns the pixels for the bitmap. The buffer that's returned will
+    // contain size().width * size().height * 4 bytes and will use Skia's byte
+    // order.
+    virtual uint8* pixels() = 0;
 };
 
 } // namespace WebKit
 
-#endif
+#endif // WebExternalBitmap_h