Move more uses of string16 to specify base::

ui/events/keycodes/keyboard_code_conversion_x.cc

 // 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.
 
 #include "ui/events/keycodes/keyboard_code_conversion_x.h"
 
 #define XK_3270  // for XK_3270_BackTab
 #include <X11/keysym.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
@@ skipping 430 matching lines @@
 const char* CodeFromXEvent(XEvent* xev) {
   return KeycodeConverter::GetInstance()->NativeKeycodeToCode(
       xev->xkey.keycode);
 }
 
 uint16 GetCharacterFromXEvent(XEvent* xev) {
   char buf[6];
   int bytes_written = XLookupString(&xev->xkey, buf, 6, NULL, NULL);
   DCHECK_LE(bytes_written, 6);
 
-  string16 result;
+  base::string16 result;
   return (bytes_written > 0 && UTF8ToUTF16(buf, bytes_written, &result) &&
           result.length() == 1) ? result[0] : 0;
 }
 
 unsigned int DefaultXKeysymFromHardwareKeycode(unsigned int hardware_code) {
   static const unsigned int kHardwareKeycodeMap[] = {
     0,                // 0x00:
     0,                // 0x01:
     0,                // 0x02:
     0,                // 0x03:
@@ skipping 339 matching lines @@
     case VKEY_KBD_BRIGHTNESS_UP:
       return XF86XK_KbdBrightnessUp;
 
     default:
       LOG(WARNING) << "Unknown keycode:" << keycode;
       return 0;
     }
 }
 
 }  // namespace ui