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

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 f5555e3f6e1020f3d1d2765b451152a3a5503530..5442c18ccb1540888409a379dd886f53127fe8b0 100644
--- a/chrome/browser/safe_browsing/protocol_manager.h
+++ b/chrome/browser/safe_browsing/protocol_manager.h
@@ -59,10 +59,10 @@ class SafeBrowsingProtocolManager : public net::URLFetcherDelegate,
   // Parameters:
   //   - The vector of full hash results. If empty, indicates that there
   //     were no matches, and that the resource is safe.
-  //   - Whether the result can be cached. This may not be the case when
-  //     the result did not come from the SB server, for example.
+  //   - The cache lifetime of the result. A lifetime of 0 indicates the results
+  //     should not be cached.
   typedef base::Callback<void(const std::vector<SBFullHashResult>&,
-                              bool)> FullHashCallback;
+                              const base::TimeDelta&)> FullHashCallback;
 
   virtual ~SafeBrowsingProtocolManager();
 
@@ -142,6 +142,15 @@ class SafeBrowsingProtocolManager : public net::URLFetcherDelegate,
     // cleared up by the full hashes.
     GET_HASH_FULL_HASH_MISS,
 
+    // Subset of successful responses where the response body wasn't parsable.
+    GET_HASH_PARSE_ERROR,
+
+    // Gethash request failed (network error).
+    GET_HASH_NETWORK_ERROR,
+
+    // Gethash request returned HTTP result code other than 200 or 204.
+    GET_HASH_HTTP_ERROR,
+
     // Memory space for histograms is determined by the max.  ALWAYS
     // ADD NEW VALUES BEFORE THIS ONE.
     GET_HASH_RESULT_MAX