Apply Ash's key rewriter to an aura::MouseEvent so that Modifler+Click is handled correctly

ash/wm/key_rewriter_event_filter.cc

 // 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 "ash/wm/key_rewriter_event_filter.h"
 
 #include "base/logging.h"
 #include "ash/key_rewriter_delegate.h"
 #include "ui/aura/event.h"
 
@@ skipping 26 matching lines @@
     case KeyRewriterDelegate::ACTION_DROP_EVENT:
       return true;
   }
 
   NOTREACHED();
   return false;
 }
 
 bool KeyRewriterEventFilter::PreHandleMouseEvent(
     aura::Window* target, aura::MouseEvent* event) {
-  return false;  // Not handled.
+  if (!delegate_.get())
+    return false;
+
+  switch (delegate_->RewriteOrFilterLocatedEvent(event)) {
+    case KeyRewriterDelegate::ACTION_REWRITE_EVENT:
+      return false;
+    case KeyRewriterDelegate::ACTION_DROP_EVENT:
+      return true;
+  }
+
+  NOTREACHED();
+  return false;
 }
 
 ui::TouchStatus KeyRewriterEventFilter::PreHandleTouchEvent(
     aura::Window* target, aura::TouchEvent* event) {
   return ui::TOUCH_STATUS_UNKNOWN;  // Not handled.
 }
 
 ui::GestureStatus KeyRewriterEventFilter::PreHandleGestureEvent(
     aura::Window* target, aura::GestureEvent* event) {
   return ui::GESTURE_STATUS_UNKNOWN;  // Not handled.
 }
 
 }  // namespace internal
 }  // namespace ash