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

chrome/browser/safe_browsing/safe_browsing_store_file.h

Index: chrome/browser/safe_browsing/safe_browsing_store_file.h
diff --git a/chrome/browser/safe_browsing/safe_browsing_store_file.h b/chrome/browser/safe_browsing/safe_browsing_store_file.h
index 22863f23a371477dd2a29e19e681e2bfec80f28c..acd477964146e1d9f194868aa8110b86b79953fb 100644
--- a/chrome/browser/safe_browsing/safe_browsing_store_file.h
+++ b/chrome/browser/safe_browsing/safe_browsing_store_file.h
@@ -143,7 +143,6 @@ class SafeBrowsingStoreFile : public SafeBrowsingStore {
 
   virtual bool WriteAddPrefix(int32 chunk_id, SBPrefix prefix) OVERRIDE;
   virtual bool WriteAddHash(int32 chunk_id,
-                            base::Time receive_time,
                             const SBFullHash& full_hash) OVERRIDE;
   virtual bool WriteSubPrefix(int32 chunk_id,
                               int32 add_chunk_id, SBPrefix prefix) OVERRIDE;
@@ -152,10 +151,9 @@ class SafeBrowsingStoreFile : public SafeBrowsingStore {
   virtual bool FinishChunk() OVERRIDE;
 
   virtual bool BeginUpdate() OVERRIDE;
-  // Store updates with pending add full hashes in file store and
-  // return |add_prefixes_result| and |add_full_hashes_result|.
+  // Store updates in file store. Kept prefixes will be added to |builder| and
+  // kept full hashes to |add_full_hashes_result|.
   virtual bool FinishUpdate(
-      const std::vector<SBAddFullHash>& pending_adds,
       safe_browsing::PrefixSetBuilder* builder,
       std::vector<SBAddFullHash>* add_full_hashes_result) OVERRIDE;
   virtual bool CancelUpdate() OVERRIDE;
@@ -185,9 +183,8 @@ class SafeBrowsingStoreFile : public SafeBrowsingStore {
   static bool DeleteStore(const base::FilePath& basename);
 
  private:
-  // Update store file with pending full hashes.
-  virtual bool DoUpdate(const std::vector<SBAddFullHash>& pending_adds,
-                        safe_browsing::PrefixSetBuilder* builder,
+  // Update store file and return |add_full_hashes_result|.
+  virtual bool DoUpdate(safe_browsing::PrefixSetBuilder* builder,
                         std::vector<SBAddFullHash>* add_full_hashes_result);
 
   // Some very lucky users have an original-format file still in their