Revert recent changes to base::Value

chrome/test/webdriver/commands/response.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 "chrome/test/webdriver/commands/response.h"
 
 #include "base/base64.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/values.h"
@@ skipping 28 matching lines @@
   int status;
   if (!data_.GetInteger(kStatusKey, &status))
     NOTREACHED();
   return static_cast<ErrorCode>(status);
 }
 
 void Response::SetStatus(ErrorCode status) {
   data_.SetInteger(kStatusKey, status);
 }
 
-Value* Response::GetValue() const {
+const Value* Response::GetValue() const {
   Value* out = NULL;
   LOG_IF(WARNING, !data_.Get(kValueKey, &out))
       << "Accessing unset response value.";  // Should never happen.
   return out;
 }
 
 void Response::SetValue(Value* value) {
   data_.Set(kValueKey, value);
 }
 
@@ skipping 10 matching lines @@
   data_.Set(key, value);
 }
 
 std::string Response::ToJSON() const {
   std::string json;
   base::JSONWriter::Write(&data_, false, &json);
   return json;
 }
 
 }  // namespace webdriver