Move trial token code to content/common.

content/public/common/content_client.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 "content/public/common/content_client.h"
 
 #include "base/logging.h"
 #include "base/strings/string_piece.h"
 #include "build/build_config.h"
 #include "content/public/common/origin_util.h"
@@ skipping 102 matching lines @@
     int sandbox_type,
     int* sandbox_profile_resource_id) const {
   return false;
 }
 #endif
 
 bool ContentClient::IsSupplementarySiteIsolationModeEnabled() {
   return false;
 }
 
+base::StringPiece ContentClient::GetOriginTrialPublicKey() {
+  return base::StringPiece();
+}
+
 }  // namespace content