Use template specialization to generate WindowProperty code

ash/touch/touch_uma.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/touch/touch_uma.h"
 
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/shell.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/stringprintf.h"
@@ skipping 28 matching lines @@
   // multi-touch gesture on the window, then this is the release-time of the
   // last touch on the window).
   base::TimeDelta last_mt_time_;
 };
 
 DEFINE_OWNED_WINDOW_PROPERTY_KEY(WindowTouchDetails,
                                  kWindowTouchDetails,
                                  NULL);
 }
 
+DECLARE_WINDOW_PROPERTY_TYPE(WindowTouchDetails*);
+
 namespace ash {
 
 // static
 TouchUMA* TouchUMA::GetInstance() {
   return Singleton<TouchUMA>::get();
 }
 
 void TouchUMA::RecordGestureEvent(aura::Window* target,
                                   const ui::GestureEvent& event) {
   GestureActionType action = FindGestureActionType(target, event);
@@ skipping 236 matching lines @@
       return GESTURE_OMNIBOX_SCROLL;
     if (event.type() == ui::ET_GESTURE_PINCH_BEGIN)
       return GESTURE_OMNIBOX_PINCH;
     return GESTURE_UNKNOWN;
   }
 
   return GESTURE_UNKNOWN;
 }
 
 }  // namespace ash