Prevent coordinate transformation when targeting the root RWHV

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <Carbon/Carbon.h>
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
@@ skipping 1561 matching lines @@
                                              transformed_point))
     return false;
   *transformed_point = gfx::ConvertPointToDIP(scale_factor, *transformed_point);
   return true;
 }
 
 bool RenderWidgetHostViewMac::TransformPointToCoordSpaceForView(
     const gfx::Point& point,
     RenderWidgetHostViewBase* target_view,
     gfx::Point* transformed_point) {
+  if (target_view == this) {
+    *transformed_point = point;
+    return true;
+  }
+
   return browser_compositor_->GetDelegatedFrameHost()
       ->TransformPointToCoordSpaceForView(point, target_view,
                                           transformed_point);
 }
 
 bool RenderWidgetHostViewMac::Send(IPC::Message* message) {
   if (render_widget_host_)
     return render_widget_host_->Send(message);
   delete message;
   return false;
@@ skipping 1846 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end