Move code in components/safe_browsing_db and chrome/browser/s_b/ under the safe_browsing namespace.

chrome/browser/safe_browsing/safe_browsing_api_handler.h

 // Copyright 2015 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.
 //
 // Glue to pass Safe Browsing API requests between
 // RemoteSafeBrowsingDatabaseManager and Java-based API to check URLs.
 
 #ifndef CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_API_HANDLER_H_
 #define CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_API_HANDLER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "chrome/browser/safe_browsing/safe_browsing_util.h"
 #include "url/gurl.h"
 
+namespace safe_browsing {
+
 class SafeBrowsingApiHandler {
  public:
   // Singleton interface.
   static void SetInstance(SafeBrowsingApiHandler* instance);
   static SafeBrowsingApiHandler* GetInstance();
 
   typedef base::Callback<void(SBThreatType sb_threat_type,
                               const std::string& metadata)> URLCheckCallback;
 
   // Makes Native->Java call and invokes callback when check is done.
   virtual void StartURLCheck(const URLCheckCallback& callback,
                              const GURL& url,
                              const std::vector<SBThreatType>& threat_types) = 0;
 
   virtual ~SafeBrowsingApiHandler() {}
 
  private:
   // Pointer not owned.
   static SafeBrowsingApiHandler* instance_;
 };
+
+}  // namespace safe_browsing
+
 #endif  // CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_API_HANDLER_H_