Rename KEY_ constants to avoid conflict with <linux/input.h>

ui/events/event.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 UI_EVENTS_EVENT_H_
 #define UI_EVENTS_EVENT_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
@@ skipping 792 matching lines @@
 
   // This allows a subclass TranslatedKeyEvent to be a non character event.
   void set_is_char(bool is_char) { is_char_ = is_char; }
 
  private:
   // Determine key_ on a keystroke event from code_ and flags().
   void ApplyLayout() const;
 
   KeyboardCode key_code_;
 
-  // DOM KeyboardEvent |code| (e.g. DomCode::KEY_A, DomCode::SPACE).
+  // DOM KeyboardEvent |code| (e.g. DomCode::US_A, DomCode::SPACE).
   // http://www.w3.org/TR/DOM-Level-3-Events-code/
   //
   // This value represents the physical position in the keyboard and can be
   // converted from / to keyboard scan code like XKB.
   DomCode code_;
 
   // True if this is a character event, false if this is a keystroke event.
   bool is_char_ = false;
 
   // TODO(kpschoedel): refactor so that key_ is not mutable.
@@ skipping 90 matching lines @@
 
   const GestureEventDetails& details() const { return details_; }
 
  private:
   GestureEventDetails details_;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_H_