Fixes bug where Env/RootWindow would cache the wrong button

ui/aura/root_window.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 "ui/aura/root_window.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 956 matching lines @@
       HandleMouseMoved(*event, target);
       break;
     case ui::ET_MOUSE_PRESSED:
       if (!mouse_pressed_handler_)
         mouse_pressed_handler_ = target;
       mouse_button_flags_ = event->flags() & kMouseButtonFlagMask;
       Env::GetInstance()->set_mouse_button_flags(mouse_button_flags_);
       break;
     case ui::ET_MOUSE_RELEASED:
       mouse_pressed_handler_ = NULL;
-      mouse_button_flags_ = event->flags() & kMouseButtonFlagMask;
+      mouse_button_flags_ = event->flags() & kMouseButtonFlagMask &
+          ~event->changed_button_flags();
       Env::GetInstance()->set_mouse_button_flags(mouse_button_flags_);
       break;
     default:
       break;
   }
   if (target && target->delegate()) {
     int flags = event->flags();
     gfx::Point location_in_window = event->location();
     Window::ConvertPointToTarget(this, target, &location_in_window);
     if (IsNonClientLocation(target, location_in_window))
@@ skipping 51 matching lines @@
 void RootWindow::UnlockCompositor() {
   DCHECK(compositor_lock_);
   compositor_lock_ = NULL;
   if (draw_on_compositor_unlock_) {
     draw_on_compositor_unlock_ = false;
     ScheduleDraw();
   }
 }
 
 }  // namespace aura