Handle timeout for update requests.

components/safe_browsing_db/v4_update_protocol_manager.h

Index: components/safe_browsing_db/v4_update_protocol_manager.h
diff --git a/components/safe_browsing_db/v4_update_protocol_manager.h b/components/safe_browsing_db/v4_update_protocol_manager.h
index 318c47693757b864fcc4ea4a97b259ab687f9259..a3b4cd538e04f24944cbbd34fa9581c05cffc1f2 100644
--- a/components/safe_browsing_db/v4_update_protocol_manager.h
+++ b/components/safe_browsing_db/v4_update_protocol_manager.h
@@ -88,6 +88,8 @@ class V4UpdateProtocolManager : public net::URLFetcherDelegate,
   FRIEND_TEST_ALL_PREFIXES(V4UpdateProtocolManagerTest,
                            TestBase64EncodingUsesUrlEncoding);
   FRIEND_TEST_ALL_PREFIXES(V4UpdateProtocolManagerTest, TestDisableAutoUpdates);
+  FRIEND_TEST_ALL_PREFIXES(V4UpdateProtocolManagerTest,
+                           TestGetUpdatesHasTimeout);
   friend class V4UpdateProtocolManagerFactoryImpl;
 
   // Fills a FetchThreatListUpdatesRequest protocol buffer for a request.
@@ -112,6 +114,10 @@ class V4UpdateProtocolManager : public net::URLFetcherDelegate,
   // Resets the update error counter and multiplier.
   void ResetUpdateErrors();
 
+  // Called when update request times out. Cancels the existing request and
+  // re-sends the update request.
+  void HandleTimeout();
+
   // Updates internal update and backoff state for each update response error,
   // assuming that the current time is |now|.
   void HandleUpdateError(const base::Time& now);
@@ -173,6 +179,10 @@ class V4UpdateProtocolManager : public net::URLFetcherDelegate,
 
   base::Time last_response_time_;
 
+  // Used to interrupt and re-schedule update requests that take too long to
+  // complete.
+  base::OneShotTimer timeout_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(V4UpdateProtocolManager);
 };