Log the size of each of the stores and complete DB on launch and after each

components/safe_browsing_db/v4_store.h

Index: components/safe_browsing_db/v4_store.h
diff --git a/components/safe_browsing_db/v4_store.h b/components/safe_browsing_db/v4_store.h
index 9775ee715d1e7e9cde346a12e6386a5d376d865c..32ee1f897233b1c2b79f2016cc9a86afd81962a3 100644
--- a/components/safe_browsing_db/v4_store.h
+++ b/components/safe_browsing_db/v4_store.h
@@ -15,7 +15,7 @@ namespace safe_browsing {
 
 class V4Store;
 
-typedef base::Callback<void(std::unique_ptr<V4Store>)>
+typedef base::Callback<void(std::unique_ptr<V4Store> new_store)>
     UpdatedStoreReadyCallback;
 
 // The sorted list of hash prefixes.
@@ -167,8 +167,12 @@ class V4Store {
   const base::FilePath& store_path() const { return store_path_; }
 
   void ApplyUpdate(std::unique_ptr<ListUpdateResponse> response,
-                   const scoped_refptr<base::SingleThreadTaskRunner>&,
-                   UpdatedStoreReadyCallback);
+                   const scoped_refptr<base::SingleThreadTaskRunner>& runner,
+                   UpdatedStoreReadyCallback callback);
+
+  // Records (in kilobytes) and returns the size of the file on disk for this
+  // store using |base_metric| as prefix and the filename as suffix.
+  int RecordAndReturnFileSize(const std::string& base_metric);

[Scott Hess - ex-Googler, 2016/10/21 23:36:45]

This should be int64_t.

[vakh (use Gerrit instead), 2016/10/24 19:39:32]

Done.

 
   // If a hash prefix in this store matches |full_hash|, returns that hash
   // prefix; otherwise returns an empty hash prefix.
@@ -374,12 +378,15 @@ class V4Store {
 
   // Writes the hash_prefix_map_ to disk as a V4StoreFileFormat proto.
   // |checksum| is used to set the |checksum| field in the final proto.
-  StoreWriteResult WriteToDisk(const Checksum& checksum) const;
+  StoreWriteResult WriteToDisk(const Checksum& checksum);
 
   // The checksum value as read from the disk, until it is verified. Once
   // verified, it is cleared.
   std::string expected_checksum_;
 
+  // The size of the file on disk for this store.
+  int file_size_;

[Scott Hess - ex-Googler, 2016/10/21 23:36:45]

This should be int64_t.

[vakh (use Gerrit instead), 2016/10/24 19:39:32]

Done.

+
   // The state of the store as returned by the PVer4 server in the last applied
   // update response.
   std::string state_;