Fix "unused variable" warnings.

content/test/mock_keyboard.cc

 // Copyright (c) 2011 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 "content/test/mock_keyboard.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
 
 namespace content {
 
-MockKeyboard::MockKeyboard()
-    : keyboard_layout_(LAYOUT_NULL),
-      keyboard_modifiers_(INVALID) {
-}
+MockKeyboard::MockKeyboard() {}
 
 MockKeyboard::~MockKeyboard() {
 }
 
 int MockKeyboard::GetCharacters(Layout layout,
                                 int key_code,
                                 Modifiers modifiers,
                                 std::wstring* output) {
 #if defined(OS_WIN)
   CHECK(output);
@@ skipping 17 matching lines @@
 
   // Retrieve Unicode characters associate with the key code.
   return driver_.GetCharacters(key_code, output);
 #else
   NOTIMPLEMENTED();
   return -1;
 #endif
 }
 
 }  // namespace content