Support for cros touchpad 3-finger click as middle button.

chrome/browser/chromeos/preferences.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 CHROME_BROWSER_CHROMEOS_PREFERENCES_H_
 #define CHROME_BROWSER_CHROMEOS_PREFERENCES_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 86 matching lines @@
   void UpdateModifierKeyMapping();
 
   // Updates the initial key repeat delay and key repeat interval following
   // current prefs values. We set the delay and interval at once since an
   // underlying XKB API requires it.
   void UpdateAutoRepeatRate();
 
   input_method::InputMethodManager* input_method_manager_;
 
   BooleanPrefMember tap_to_click_enabled_;
+  BooleanPrefMember three_finger_click_enabled_;
   BooleanPrefMember natural_scroll_;
   BooleanPrefMember vert_edge_scroll_enabled_;
   BooleanPrefMember accessibility_enabled_;
   IntegerPrefMember speed_factor_;
   IntegerPrefMember mouse_sensitivity_;
   IntegerPrefMember touchpad_sensitivity_;
   BooleanPrefMember primary_mouse_button_right_;
   BooleanPrefMember use_24hour_clock_;
   BooleanPrefMember disable_gdata_;
   BooleanPrefMember disable_gdata_over_cellular_;
@@ skipping 34 matching lines @@
   IntegerPrefMember xkb_auto_repeat_interval_pref_;
 
   BooleanPrefMember enable_screen_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(Preferences);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_PREFERENCES_H_