Move EmptyString, kWhitespace and the BOM to base.

content/renderer/media/crypto/proxy_decryptor.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 "content/renderer/media/crypto/proxy_decryptor.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
@@ skipping 237 matching lines @@
     return sessions_.begin()->first;
 
   return INVALID_REFERENCE_ID;
 }
 
 const std::string& ProxyDecryptor::LookupSessionId(uint32 reference_id) {
   DCHECK_NE(reference_id, INVALID_REFERENCE_ID);
 
   // Session may not exist if error happens during GenerateKeyRequest().
   SessionIdMap::iterator it = sessions_.find(reference_id);
-  return (it != sessions_.end()) ? it->second : EmptyString();
+  return (it != sessions_.end()) ? it->second : base::EmptyString();
 }
 
 }  // namespace content