[Slimming Paint] Paint the inspector overlay with GraphicsLayer DisplayList.

public/web/WebPageOverlay.h

 /*
  * Copyright (C) 2011 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.
  *
@@ skipping 11 matching lines @@
  * 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 WebPageOverlay_h
 #define WebPageOverlay_h
 
-#include "../platform/WebCanvas.h"
-#include "../platform/WebRect.h"
+#include "public/platform/WebCanvas.h"
+#include "public/platform/WebCommon.h"
 
 namespace blink {
 
-class WebPageOverlay {
+class WebGraphicsContext;
+struct WebSize;
+
+class BLINK_EXPORT WebPageOverlay {
 public:
     // Paints page overlay contents.
-    virtual void paintPageOverlay(WebCanvas*) = 0;
+    // FIXME: Once Chromium no longer uses the WebCanvas* overload:
+    // - remove it
+    // - make the WebGraphicsContext* overload pure virtual
+    // - remove the BLINK_EXPORT tag from this class
+    virtual void paintPageOverlay(WebGraphicsContext*, const WebSize& webViewSize);
+    virtual void paintPageOverlay(WebCanvas*);
 
 protected:
     virtual ~WebPageOverlay() { }
 };
 
 } // namespace blink
 
 #endif // WebPageOverlay_h