Introduce HistoryClient interface

chrome/browser/history/chrome_history_client.h

Index: chrome/browser/history/chrome_history_client.h
diff --git a/chrome/browser/history/chrome_history_client.h b/chrome/browser/history/chrome_history_client.h
new file mode 100644
index 0000000000000000000000000000000000000000..f6f8d35f1ee3881ae7923044b7537f6a906db91a
--- /dev/null
+++ b/chrome/browser/history/chrome_history_client.h
@@ -0,0 +1,19 @@
+// Copyright 2014 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.
+
+#ifndef CHROME_BROWSER_HISTORY_CHROME_HISTORY_CLIENT_H_
+#define CHROME_BROWSER_HISTORY_CHROME_HISTORY_CLIENT_H_
+
+#include "base/macros.h"
+#include "components/history/core/browser/history_client.h"
+
+class ChromeHistoryClient : public history::HistoryClient {
+ public:
+  ChromeHistoryClient();
+
+ protected:
+  DISALLOW_COPY_AND_ASSIGN(ChromeHistoryClient);
+};
+
+#endif  // CHROME_BROWSER_HISTORY_CHROME_HISTORY_CLIENT_H_