Safebrowsing: change gethash caching to match api 2.3 rules, fix some corner cases.

chrome/browser/safe_browsing/database_manager.h

Index: chrome/browser/safe_browsing/database_manager.h
diff --git a/chrome/browser/safe_browsing/database_manager.h b/chrome/browser/safe_browsing/database_manager.h
index a8d8bad42668b62da57033bc76def4830038ff2a..c117ce1c4ca2227694ae9b49b3366803197a313e 100644
--- a/chrome/browser/safe_browsing/database_manager.h
+++ b/chrome/browser/safe_browsing/database_manager.h
@@ -76,7 +76,7 @@ class SafeBrowsingDatabaseManager
     safe_browsing_util::ListType check_type;  // See comment in constructor.
     std::vector<SBThreatType> expected_threats;
     std::vector<SBPrefix> prefix_hits;
-    std::vector<SBFullHashResult> full_hits;
+    std::vector<SBFullHashResult> cache_hits;
 
     // Vends weak pointers for TimeoutCallback().  If the response is
     // received before the timeout fires, factory is destructed and
@@ -179,10 +179,9 @@ class SafeBrowsingDatabaseManager
 
   // Called on the IO thread when the SafeBrowsingProtocolManager has received
   // the full hash results for prefix hits detected in the database.
-  void HandleGetHashResults(
-      SafeBrowsingCheck* check,
-      const std::vector<SBFullHashResult>& full_hashes,
-      bool can_cache);
+  void HandleGetHashResults(SafeBrowsingCheck* check,
+                            const std::vector<SBFullHashResult>& full_hashes,
+                            const base::TimeDelta& cache_lifetime);
 
   // Log the user perceived delay caused by SafeBrowsing. This delay is the time
   // delta starting from when we would have started reading data from the
@@ -292,7 +291,8 @@ class SafeBrowsingDatabaseManager
 
   // Store in-memory the GetHash response. Runs on the database thread.
   void CacheHashResults(const std::vector<SBPrefix>& prefixes,
-                        const std::vector<SBFullHashResult>& full_hashes);
+                        const std::vector<SBFullHashResult>& full_hashes,
+                        const base::TimeDelta& cache_lifetime);
 
   // Internal worker function for processing full hashes.
   void OnHandleGetHashResults(SafeBrowsingCheck* check,