Move full hash caching logic to v4_get_hash_protocol_manager

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 fc94642d31277f86f30d0684592178c693e331aa..d4559780cae063ccfeae55d8a14f29f33bff8082 100644
--- a/components/safe_browsing_db/v4_store.h
+++ b/components/safe_browsing_db/v4_store.h
@@ -18,10 +18,6 @@ class V4Store;
 typedef base::Callback<void(std::unique_ptr<V4Store>)>
     UpdatedStoreReadyCallback;
 
-// The size of the hash prefix, in bytes. It should be between 4 to 32 (full
-// hash).
-typedef size_t PrefixSize;
-
 // The sorted list of hash prefixes.
 typedef std::string HashPrefixes;