Adding tools menu responsiveness metric.

ios/shared/chrome/browser/ui/tools_menu/tools_menu_configuration.h

 // Copyright 2016 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 IOS_SHARED_CHROME_BROWSER_UI_TOOLS_MENU_TOOLS_MENU_CONFIGURATION_H_
 #define IOS_SHARED_CHROME_BROWSER_UI_TOOLS_MENU_TOOLS_MENU_CONFIGURATION_H_
 
 #import <Foundation/Foundation.h>
 #import <UIKit/UIKit.h>
 
@@ skipping 26 matching lines @@
 @property(nonatomic, assign) UIButton* toolsMenuButton;
 // Menu's origin relative to the |displayView|'s coordinate system, calculated
 // from |toolsMenuButton| and |displayView|.
 @property(nonatomic, readonly) CGRect sourceRect;
 // Image insets that should be applied to the tools button if it is displayed,
 // calculated from |toolsMenuButton|.
 @property(nonatomic, readonly) UIEdgeInsets toolsButtonInsets;
 // Notifier for changes to the reading list requiring the menu to be updated.
 // Menus needing to be updated should set themselves as this object's delegate.
 @property(nonatomic, assign) ReadingListMenuNotifier* readingListMenuNotifier;
+// Records the time that the tools menu was requested; value is the time
+// interval since the NSDate referenceDate.
+@property(nonatomic, assign) NSTimeInterval requestStartTime;
 
 // Initialize a ToolsMenuContext instance with default values. |displayView| is
 // the weakly-held parent view within which the popup tools menu using this
 // context will be displayed.
 - (instancetype)initWithDisplayView:(UIView*)displayView
     NS_DESIGNATED_INITIALIZER;
 - (instancetype)init NS_UNAVAILABLE;
 
 @end
 
 #endif  // IOS_SHARED_CHROME_BROWSER_UI_TOOLS_MENU_TOOLS_MENU_CONFIGURATION_H_