Makes AKEYCODE_BACK map to VKEY_BROWSER_BACK

ui/events/keycodes/keyboard_code_conversion_android.cc

 // Copyright 2013 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.
 
 #include "ui/events/keycodes/keyboard_code_conversion_android.h"
 
 #include <android/keycodes.h>
 
 namespace ui {
 
@@ skipping 59 matching lines @@
       return VKEY_TAB;
     case AKEYCODE_CLEAR:
       return VKEY_CLEAR;
     case AKEYCODE_DPAD_CENTER:
     case AKEYCODE_ENTER:
       return VKEY_RETURN;
     case AKEYCODE_SHIFT_LEFT:
       return VKEY_LSHIFT;
     case AKEYCODE_SHIFT_RIGHT:
       return VKEY_RSHIFT;
-    // Back will serve as escape, although we may not have access to it.
     case AKEYCODE_BACK:
-      return VKEY_ESCAPE;
+      return VKEY_BROWSER_BACK;
     case AKEYCODE_SPACE:
       return VKEY_SPACE;
     case AKEYCODE_MOVE_HOME:
       return VKEY_HOME;
     case AKEYCODE_DPAD_LEFT:
       return VKEY_LEFT;
     case AKEYCODE_DPAD_UP:
       return VKEY_UP;
     case AKEYCODE_DPAD_RIGHT:
       return VKEY_RIGHT;
@@ skipping 205 matching lines @@
     case AKEYCODE_CHANNEL_UP:
       return VKEY_PRIOR;
     case AKEYCODE_CHANNEL_DOWN:
       return VKEY_NEXT;
     default:
       return VKEY_UNKNOWN;
   }
 }
 
 }  // namespace ui