Move TopSites api from c/b/history to c/b/e/api

chrome/browser/extensions/api/top_sites/top_sites_api.h

 // 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.
 
-#ifndef CHROME_BROWSER_HISTORY_TOP_SITES_EXTENSION_API_H_
-#define CHROME_BROWSER_HISTORY_TOP_SITES_EXTENSION_API_H_
+#ifndef CHROME_BROWSER_EXTENSIONS_API_TOP_SITES_TOP_SITES_API_H_
+#define CHROME_BROWSER_EXTENSIONS_API_TOP_SITES_TOP_SITES_API_H_
 
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/extensions/extension_function.h"
 #include "chrome/browser/history/history_types.h"
 
+namespace extensions {
+
 class GetTopSitesFunction : public AsyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME("topSites.get")
 
   GetTopSitesFunction();
 
  protected:
   virtual ~GetTopSitesFunction();
 
   // ExtensionFunction:
   virtual bool RunImpl() OVERRIDE;
 
  private:
   void OnMostVisitedURLsAvailable(const history::MostVisitedURLList& data);
 
   // For callbacks may be run after destruction.
   base::WeakPtrFactory<GetTopSitesFunction> weak_ptr_factory_;
 };
 
-#endif  // CHROME_BROWSER_HISTORY_TOP_SITES_EXTENSION_API_H_
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_TOP_SITES_TOP_SITES_API_H_