Don't check URLs against Safe Browsing if not supported.

chrome/browser/safe_browsing/test_database_manager.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.
 
 #ifndef CHROME_BROWSER_SAFE_BROWSING_TEST_DATABASE_MANAGER_H_
 #define CHROME_BROWSER_SAFE_BROWSING_TEST_DATABASE_MANAGER_H_
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "chrome/browser/safe_browsing/database_manager.h"
 
 // This is a non-pure-virtual implementation of the SafeBrowsingDatabaseManager
 // interface.  It's used in tests by overriding only the functions that get
 // called, and it'll complain if you call one that isn't overriden.
 class TestSafeBrowsingDatabaseManager
     : public SafeBrowsingDatabaseManager {
  public:
   // SafeBrowsingDatabaseManager implementation:
+  bool IsSupported() const override;
   bool CanCheckUrl(const GURL& url) const override;
   bool download_protection_enabled() const override;
   bool CheckBrowseUrl(const GURL& url, Client* client) override;
   bool CheckDownloadUrl(const std::vector<GURL>& url_chain,
                         Client* client) override;
   bool CheckExtensionIDs(const std::set<std::string>& extension_ids,
                          Client* client) override;
   bool MatchCsdWhitelistUrl(const GURL& url) override;
   bool MatchMalwareIP(const std::string& ip_address) override;
   bool MatchDownloadWhitelistUrl(const GURL& url) override;
   bool MatchDownloadWhitelistString(const std::string& str) override;
   bool MatchInclusionWhitelistUrl(const GURL& url) override;
   bool IsMalwareKillSwitchOn() override;
   bool IsCsdWhitelistKillSwitchOn() override;
   void CancelCheck(Client* client) override;
   void StartOnIOThread() override;
   void StopOnIOThread(bool shutdown) override;
 
  protected:
   ~TestSafeBrowsingDatabaseManager() override {};
 };
 #endif  // CHROME_BROWSER_SAFE_BROWSING_TEST_DATABASE_MANAGER_H_