[Merge] Make mouse buttons 8 - 11 navigate forward and back in history

ui/events/ozone/evdev/event_modifiers_evdev.h

 // Copyright 2014 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 UI_EVENTS_OZONE_EVDEV_EVENT_MODIFIERS_EVDEV_H_
 #define UI_EVENTS_OZONE_EVDEV_EVENT_MODIFIERS_EVDEV_H_
 
 #include "base/basictypes.h"
 #include "ui/events/ozone/evdev/events_ozone_evdev_export.h"
 
 namespace ui {
 
 enum {
   EVDEV_MODIFIER_NONE,
   EVDEV_MODIFIER_CAPS_LOCK,
   EVDEV_MODIFIER_SHIFT,
   EVDEV_MODIFIER_CONTROL,
   EVDEV_MODIFIER_ALT,
   EVDEV_MODIFIER_LEFT_MOUSE_BUTTON,
   EVDEV_MODIFIER_MIDDLE_MOUSE_BUTTON,
   EVDEV_MODIFIER_RIGHT_MOUSE_BUTTON,
+  EVDEV_MODIFIER_BACK_MOUSE_BUTTON,
+  EVDEV_MODIFIER_FORWARD_MOUSE_BUTTON,
   EVDEV_MODIFIER_COMMAND,
   EVDEV_MODIFIER_ALTGR,
   EVDEV_MODIFIER_MOD3,
   EVDEV_NUM_MODIFIERS
 };
 
 // Modifier key state for Evdev.
 //
 // Chrome relies on the underlying OS to interpret modifier keys such as Shift,
 // Ctrl, and Alt. The Linux input subsystem does not assign any special meaning
@@ skipping 40 matching lines @@
 
   // Update modifier_flags_ from modifiers_down_ and modifier_flags_locked_.
   void UpdateFlags(unsigned int modifier);
 
   DISALLOW_COPY_AND_ASSIGN(EventModifiersEvdev);
 };
 
 }  // namspace ui
 
 #endif  // UI_EVENTS_OZONE_EVDEV_EVENT_MODIFIERS_EVDEV_H_