Fully support the autohide shelf option for touch UI on Windows.

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 40 matching lines @@
   UMA_ET_GESTURE_MULTIFINGER_SWIPE_3,
   UMA_ET_GESTURE_MULTIFINGER_SWIPE_4P,  // 4+ fingers
   UMA_ET_GESTURE_SCROLL_UPDATE_2,
   UMA_ET_GESTURE_SCROLL_UPDATE_3,
   UMA_ET_GESTURE_SCROLL_UPDATE_4P,
   UMA_ET_GESTURE_PINCH_UPDATE_3,
   UMA_ET_GESTURE_PINCH_UPDATE_4P,
   UMA_ET_GESTURE_LONG_TAP,
   UMA_ET_GESTURE_SHOW_PRESS,
   UMA_ET_GESTURE_TAP_CANCEL,
+  UMA_ET_GESTURE_WIN8_EDGE_SWIPE,
   // NOTE: Add new event types only immediately above this line. Make sure to
-  // update the enum list in tools/metrics/histogram/histograms.xml accordingly.
+  // update the UIEventType enum in tools/metrics/histograms/histograms.xml
+  // accordingly.
   UMA_ET_COUNT
 };
 
 struct WindowTouchDetails {
   WindowTouchDetails()
       : max_distance_from_start_squared_(0) {
   }
 
   // Move and start times of the touch points. The key is the touch-id.
   std::map<int, base::TimeDelta> last_move_time_;
@@ skipping 88 matching lines @@
       return UMA_ET_GESTURE_LONG_TAP;
     case ui::ET_GESTURE_MULTIFINGER_SWIPE: {
       const ui::GestureEvent& gesture =
           static_cast<const ui::GestureEvent&>(event);
       if (gesture.details().touch_points() >= 4)
         return UMA_ET_GESTURE_MULTIFINGER_SWIPE_4P;
       else if (gesture.details().touch_points() == 3)
         return UMA_ET_GESTURE_MULTIFINGER_SWIPE_3;
       return UMA_ET_GESTURE_MULTIFINGER_SWIPE;
     }
+    case ui::ET_GESTURE_WIN8_EDGE_SWIPE:
+      return UMA_ET_GESTURE_WIN8_EDGE_SWIPE;
     case ui::ET_GESTURE_TAP_CANCEL:
       return UMA_ET_GESTURE_TAP_CANCEL;
     case ui::ET_GESTURE_SHOW_PRESS:
       return UMA_ET_GESTURE_SHOW_PRESS;
     case ui::ET_SCROLL:
       return UMA_ET_SCROLL;
     case ui::ET_SCROLL_FLING_START:
       return UMA_ET_SCROLL_FLING_START;
     case ui::ET_SCROLL_FLING_CANCEL:
       return UMA_ET_SCROLL_FLING_CANCEL;
@@ skipping 279 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