[Mac] Add two-finger gesture support for Lion, which respects the system preference.

chrome/browser/ui/cocoa/browser_window_controller.h

 // Copyright (c) 2011 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 CHROME_BROWSER_UI_COCOA_BROWSER_WINDOW_CONTROLLER_H_
 #define CHROME_BROWSER_UI_COCOA_BROWSER_WINDOW_CONTROLLER_H_
 #pragma once
 
 // A class acting as the Objective-C controller for the Browser
 // object. Handles interactions between Cocoa and the cross-platform
@@ skipping 29 matching lines @@
 @class InfoBarContainerController;
 class LocationBarViewMac;
 @class PreviewableContentsController;
 @class SidebarController;
 class StatusBubbleMac;
 class TabContents;
 @class TabStripController;
 @class TabStripView;
 @class ToolbarController;
 
-
 @interface BrowserWindowController :
   TabWindowController<NSUserInterfaceValidations,
                       BookmarkBarControllerDelegate,
                       BrowserCommandExecutor,
                       ViewResizer,
                       TabContentsControllerDelegate,
                       TabStripControllerDelegate> {
  @private
   // The ordering of these members is important as it determines the order in
   // which they are destroyed. |browser_| needs to be destroyed last as most of
@@ skipping 28 matching lines @@
   // away from the bottom/top or resized (or zoomed).
   CGFloat windowTopGrowth_;
   CGFloat windowBottomGrowth_;
 
   // YES only if we're shrinking the window from an apparent zoomed state (which
   // we'll only do if we grew it to the zoomed state); needed since we'll then
   // restrict the amount of shrinking by the amounts specified above. Reset to
   // NO on growth.
   BOOL isShrinkingFromZoomed_;
 
+  // Touch event data for two-finger gestures. Only available on Lion or higher
+  // with two-finger gestures enabled in the Trackpad preferences. This will
+  // contain the NSTouch objects from |-beginGestureWithEvent:| keyed by the
+  // touch's |identity|.
+  scoped_nsobject<NSMutableDictionary> twoFingerGestureTouches_;
+
   // The raw accumulated zoom value and the actual zoom increments made for an
   // an in-progress pinch gesture.
   CGFloat totalMagnifyGestureAmount_;
   NSInteger currentZoomStepDelta_;
 
   // The view that shows the incognito badge or the multi-profile avatar icon.
   // Nil if neither is present. Needed to access the view to move it to/from the
   // fullscreen window.
   scoped_nsobject<AvatarButton> avatarButton_;
 
@@ skipping 297 matching lines @@
 - (void)resetWindowGrowthState;
 
 // Computes by how far in each direction, horizontal and vertical, the
 // |source| rect doesn't fit into |target|.
 - (NSSize)overflowFrom:(NSRect)source
                     to:(NSRect)target;
 @end  // @interface BrowserWindowController (TestingAPI)
 
 
 #endif  // CHROME_BROWSER_UI_COCOA_BROWSER_WINDOW_CONTROLLER_H_