Delete prefix-set if side-effect-free whitelist not enabled.

The code was correctly deleting the main safe-browsing store in this
case, but left the associated filter file stranded.

BUG=none
R=tburkard@chromium.org

Review URL: https://codereview.chromium.org/341553006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278253 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/safe_browsing/safe_browsing_database.cc

@@ -594,6 +594,9 @@ void SafeBrowsingDatabaseNew::Init(const base::FilePath& filename_base) {
     // from when it was previously enabled.
     SafeBrowsingStoreFile::DeleteStore(
         SideEffectFreeWhitelistDBFilename(filename_base));
+    base::DeleteFile(
+        PrefixSetForFilename(SideEffectFreeWhitelistDBFilename(filename_base)),
+        false);
   }
 
   if (ip_blacklist_store_.get()) {