Sync/Valgrind: Add gmock printers for SyncChange, SyncData, SyncError.

chrome/browser/sync/api/sync_change.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/browser/sync/api/sync_change.h"
 
+#include <ostream>
+
 SyncChange::SyncChange() : change_type_(ACTION_INVALID) {
 }
 
 SyncChange::SyncChange(SyncChangeType change_type, const SyncData& sync_data)
     : change_type_(change_type),
       sync_data_(sync_data) {
   DCHECK(IsValid());
 }
 
 SyncChange::~SyncChange() {}
@@ skipping 35 matching lines @@
       return "ACTION_ADD";
     case ACTION_UPDATE:
       return "ACTION_UPDATE";
     case ACTION_DELETE:
       return "ACTION_DELETE";
     default:
       NOTREACHED();
   }
   return std::string();
 }
+
+std::string SyncChange::ToString() const {
+  return "{ changeType: " + ChangeTypeToString(change_type_) +
+      ", syncData: " + sync_data_.ToString() + "}";
+}
+
+void PrintTo(const SyncChange& sync_change, std::ostream* os) {
+  *os << sync_change.ToString();
+}