Add touchpad sensitivity setting.

chrome/browser/chromeos/touchpad.h

 // Copyright (c) 2006-2008 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_TOUCHPAD_H_
 #define CHROME_BROWSER_CHROMEOS_TOUCHPAD_H_
 
 #include <string>
 
 #include "chrome/common/notification_observer.h"
@@ skipping 25 matching lines @@
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
  protected:
   virtual void NotifyPrefChanged(const std::wstring* pref_name);
 
  private:
   // This methods makes a system call to synclient to change touchpad settings.
   // The system call will be invoked on the file thread.
-  void SetSynclientParam(const std::string& param, const std::string& value);
+  void SetSynclientParam(const std::string& param, double value);
 
-  // Set tap-to-click to value stored in preference.
+  // Set tap-to-click to value stored in preferences.
   void SetTapToClick();
 
-  // Set vertical edge scrolling to value stored in preference.
+  // Set vertical edge scrolling to value stored in preferences.
   void SetVertEdgeScroll();
 
-  // Set touchpad speed factor to value stored in preference.
+  // Set touchpad speed factor to value stored in preferences.
   void SetSpeedFactor();
 
+  // Set tap sensitivity to value stored in preferences.
+  void SetSensitivity();
+
   BooleanPrefMember tap_to_click_enabled_;
   BooleanPrefMember vert_edge_scroll_enabled_;
-  RealPrefMember speed_factor_;
+  IntegerPrefMember speed_factor_;
+  IntegerPrefMember sensitivity_;
 
   DISALLOW_COPY_AND_ASSIGN(Touchpad);
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_TOUCHPAD_H_