Allow DrawingBuffer to present to a bitmap.

public/platform/WebExternalBitmap.h

Index: public/platform/WebExternalBitmap.h
diff --git a/public/web/WebDOMResourceProgressEvent.h b/public/platform/WebExternalBitmap.h
similarity index 74%
copy from public/web/WebDOMResourceProgressEvent.h
copy to public/platform/WebExternalBitmap.h
index b65d93c80e006d6e99c837e840eb38cb3a71055d..147081532b0f71d13f61d862d7df172890f8486a 100644
--- a/public/web/WebDOMResourceProgressEvent.h
+++ b/public/platform/WebExternalBitmap.h
@@ -28,21 +28,27 @@
  * 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 WebDOMResourceProgressEvent : public WebDOMProgressEvent {
+class WebExternalBitmap {
 public:
-    WebDOMResourceProgressEvent() { }
-    WEBKIT_EXPORT WebDOMResourceProgressEvent(const WebString& type, bool lengthIsComputable, unsigned long long loaded, unsigned long long total, const WebString& url);
+    virtual WebSize size() = 0;
+
+    // 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