Fix a UMR that happens while trying to forward mouse events.

chrome/browser/renderer_host/render_view_host.cc

 // Copyright (c) 2009 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 "chrome/browser/renderer_host/render_view_host.h"
 
 #include <string>
 #include <vector>
 
 #include "app/resource_bundle.h"
@@ skipping 1393 matching lines @@
 void RenderViewHost::NotifyRendererResponsive() {
   delegate_->RendererResponsive(this);
 }
 
 gfx::Rect RenderViewHost::GetRootWindowResizerRect() const {
   return delegate_->GetRootWindowResizerRect();
 }
 
 void RenderViewHost::ForwardMouseEvent(
     const WebKit::WebMouseEvent& mouse_event) {
-  RenderWidgetHost::ForwardMouseEvent(mouse_event);
+  // We make a copy of the mouse event because
+  // RenderWidgetHost::ForwardMouseEvent will delete |mouse_event|.
+  WebKit::WebMouseEvent event_copy(mouse_event);
+  RenderWidgetHost::ForwardMouseEvent(event_copy);
 
   RenderViewHostDelegate::View* view = delegate_->GetViewDelegate();
   if (view) {
-    switch (mouse_event.type) {
+    switch (event_copy.type) {
       case WebInputEvent::MouseMove:
         view->HandleMouseEvent();
         break;
       case WebInputEvent::MouseLeave:
         view->HandleMouseLeave();
         break;
       default:
         // For now, we don't care about the rest.
         break;
     }
@@ skipping 47 matching lines @@
 }
 
 void RenderViewHost::OnAccessibilityFocusChange(int acc_obj_id) {
 #if defined(OS_WIN)
   BrowserAccessibilityManager::GetInstance()->
       ChangeAccessibilityFocus(acc_obj_id, process()->pid(), routing_id());
 #else
   // TODO(port): accessibility not yet implemented. See http://crbug.com/8288.
 #endif
 }