linux and chromeos: Turn on -Wunused-const-variable.

chromeos/ime/xkeyboard.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 "chromeos/ime/xkeyboard.h"
 
 #include <cstdlib>
 #include <cstring>
 #include <queue>
 #include <set>
@@ skipping 15 matching lines @@
 #include <glib.h>
 
 namespace chromeos {
 namespace input_method {
 namespace {
 
 Display* GetXDisplay() {
   return base::MessagePumpForUI::GetDefaultXDisplay();
 }
 
-// The default keyboard layout name in the xorg config file.
-const char kDefaultLayoutName[] = "us";
-
 // The command we use to set the current XKB layout and modifier key mapping.
 // TODO(yusukes): Use libxkbfile.so instead of the command (crosbug.com/13105)
 const char kSetxkbmapCommand[] = "/usr/bin/setxkbmap";
 
 // A string for obtaining a mask value for Num Lock.
 const char kNumLockVirtualModifierString[] = "NumLock";
 
 // Returns false if |layout_name| contains a bad character.
 bool CheckLayoutName(const std::string& layout_name) {
   static const char kValidLayoutNameCharacters[] =
@@ skipping 321 matching lines @@
   return CheckLayoutName(layout_name);
 }
 
 // static
 XKeyboard* XKeyboard::Create() {
   return new XKeyboardImpl();
 }
 
 }  // namespace input_method
 }  // namespace chromeos