Add dedicated windowToViewport method

third_party/WebKit/public/web/WebWidgetClient.h

 /*
  * Copyright (C) 2009 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 30 matching lines @@
 #include "public/web/WebTouchAction.h"
 
 namespace blink {
 
 class WebGestureEvent;
 class WebNode;
 class WebString;
 class WebWidget;
 struct WebCursorInfo;
 struct WebFloatPoint;
+struct WebFloatRect;
 struct WebFloatSize;
 struct WebSize;
 
 class WebWidgetClient {
 public:
     // Called when a region of the WebWidget needs to be re-painted.
     virtual void didInvalidateRect(const WebRect&) { }
 
     // Called when the Widget has changed size as a result of an auto-resize.
     virtual void didAutoResize(const WebSize& newSize) { }
@@ skipping 107 matching lines @@
     // press or gesture tap.
     // Note: This is called even when the mouse down event is prevent default.
     virtual void onMouseDown(const WebNode& mouseDownNode) { }
 
     // Converts the |rect| from Blink's Viewport coordinates to the
     // coordinates in the native window used to display the content, in
     // DIP.  They're identical in tradional world, but will differ when
     // use-zoom-for-dsf feature is eanbled, and Viewport coordinates
     // becomes DSF times larger than window coordinates.
     // TODO(oshima): Update the comment when the migration is completed.
     virtual void convertViewportToWindow(WebRect* rect) {}

[dgozman, 2016/01/26 00:17:45]

Perhaps, this one should work with WebFloatRect as well? Or is it deliberately
left as WebRect?
This does not affect this patch though.

[oshima, 2016/01/26 00:24:00]

Sorry I forgot to mention. Yes, I'm going to change this
(https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/r...)

 
+    // Converts the |rect| from the coordinates in native window in
+    // DIP to Blink's Viewport coordinates. They're identical in
+    // tradional world, but will differ when use-zoom-for-dsf feature
+    // is eanbled.  TODO(oshima): Update the comment when the
+    // migration is completed.
+    virtual void convertWindowToViewport(WebFloatRect* rect) {}
+
 protected:
     ~WebWidgetClient() { }
 };
 
 } // namespace blink
 
 #endif