Add UMA metrics for window selection and overview.

ash/shell_delegate.h

 // 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.
 
 #ifndef ASH_SHELL_DELEGATE_H_
 #define ASH_SHELL_DELEGATE_H_
 
 #include <string>
 
 #include "ash/ash_export.h"
@@ skipping 71 matching lines @@
   UMA_WINDOW_MAXIMIZE_BUTTON_CLICK_EXIT_FULLSCREEN,
   UMA_WINDOW_MAXIMIZE_BUTTON_CLICK_MAXIMIZE,
   UMA_WINDOW_MAXIMIZE_BUTTON_CLICK_MINIMIZE,
   UMA_WINDOW_MAXIMIZE_BUTTON_CLICK_RESTORE,
   UMA_WINDOW_MAXIMIZE_BUTTON_MAXIMIZE,
   UMA_WINDOW_MAXIMIZE_BUTTON_MAXIMIZE_LEFT,
   UMA_WINDOW_MAXIMIZE_BUTTON_MAXIMIZE_RIGHT,
   UMA_WINDOW_MAXIMIZE_BUTTON_MINIMIZE,
   UMA_WINDOW_MAXIMIZE_BUTTON_RESTORE,
   UMA_WINDOW_MAXIMIZE_BUTTON_SHOW_BUBBLE,
+
+  // Thumbnail sized overview of windows triggered. This is a subset of
+  // UMA_WINDOW_SELECTION triggered by lingering during alt+tab cycles or
+  // pressing the overview key.
+  UMA_WINDOW_OVERVIEW,
+
+  // Window selection started by beginning an alt+tab cycle or pressing the
+  // overview key. This does not count each step through an alt+tab cycle.
+  UMA_WINDOW_SELECTION,
 };
 
 enum AccessibilityNotificationVisibility {
   A11Y_NOTIFICATION_NONE,
   A11Y_NOTIFICATION_SHOW,
 };
 
 // Delegate of the Shell.
 class ASH_EXPORT ShellDelegate {
  public:
@@ skipping 146 matching lines @@
   // value.
   virtual RootWindowHostFactory* CreateRootWindowHostFactory() = 0;
 
   // Get the product name.
   virtual base::string16 GetProductName() const = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_DELEGATE_H_