Adds backoff and Min Wait Duration compliance to Protocolmanager pver4 handlers.

chrome/browser/safe_browsing/protocol_manager.h

Index: chrome/browser/safe_browsing/protocol_manager.h
diff --git a/chrome/browser/safe_browsing/protocol_manager.h b/chrome/browser/safe_browsing/protocol_manager.h
index fe354284b81f6e4f91571023dcbbb046a537457c..579f26b241703e6c062ab4aea71b1523fc99fd2e 100644
--- a/chrome/browser/safe_browsing/protocol_manager.h
+++ b/chrome/browser/safe_browsing/protocol_manager.h
@@ -216,6 +216,8 @@ class SafeBrowsingProtocolManager : public net::URLFetcherDelegate,
                            TestParseV4HashResponseNonPermissionMetadata);
   FRIEND_TEST_ALL_PREFIXES(SafeBrowsingProtocolManagerTest,
                            TestGetHashBackOffTimes);
+  FRIEND_TEST_ALL_PREFIXES(SafeBrowsingProtocolManagerTest,
+                           TestGetV4HashBackOffTimes);
   FRIEND_TEST_ALL_PREFIXES(SafeBrowsingProtocolManagerTest, TestNextChunkUrl);
   FRIEND_TEST_ALL_PREFIXES(SafeBrowsingProtocolManagerTest, TestUpdateUrl);
   friend class SafeBrowsingServerTest;
@@ -284,6 +286,12 @@ class SafeBrowsingProtocolManager : public net::URLFetcherDelegate,
   base::TimeDelta GetNextBackOffInterval(size_t* error_count,
                                          size_t* multiplier) const;
 
+  // Worker function for calculating the V4 GetHash backoff times.
+  // |multiplier| is doubled for each consecutive error after the
+  // first, and |error_count| is incremented with each call.
+  static base::TimeDelta GetNextV4BackOffInterval(size_t* error_count,
+                                                  size_t* multiplier);
+
   // Manages our update with the next allowable update time. If 'back_off_' is
   // true, we must decrease the frequency of requests of the SafeBrowsing
   // service according to section 5 of the protocol specification.
@@ -318,6 +326,10 @@ class SafeBrowsingProtocolManager : public net::URLFetcherDelegate,
   // current time is |now|.
   void HandleGetHashError(const base::Time& now);
 
+  // Updates internal state for each GetHash V4 response error, assuming that
+  // the current time is |now|.
+  void HandleGetHashV4Error(const base::Time& now);
+
   // Helper function for update completion.
   void UpdateFinished(bool success);
   void UpdateFinished(bool success, bool back_off);
@@ -359,10 +371,12 @@ class SafeBrowsingProtocolManager : public net::URLFetcherDelegate,
   // The number of HTTP response errors, used for request backoff timing.

[Nathan Parker, 2016/01/12 04:14:38]

number of HTTP response error since the last successful HTTP response (ya?)

[kcarattini, 2016/01/12 05:18:06]

Done.

   size_t update_error_count_;
   size_t gethash_error_count_;
+  size_t gethash_v4_error_count_;
 
   // Multipliers which double (max == 8) for each error after the second.
   size_t update_back_off_mult_;
   size_t gethash_back_off_mult_;
+  size_t gethash_v4_back_off_mult_;
 
   // Multiplier between 0 and 1 to spread clients over an interval.
   float back_off_fuzz_;
@@ -394,6 +408,7 @@ class SafeBrowsingProtocolManager : public net::URLFetcherDelegate,
 
   // While in GetHash backoff, we can't make another GetHash until this time.
   base::Time next_gethash_time_;
+  base::Time next_gethash_v4_time_;

[Nathan Parker, 2016/01/12 04:14:38]

Is this the max of the prescribed min-wait-time and the backoff time?

[kcarattini, 2016/01/12 05:18:06]

No, it should be one or the other. Added a comment.

 
   // Current product version sent in each request.
   std::string version_;