Subsituting pattern ScopedVector push_back.(ptr.release()) with push_back(ptr.Pass()) in indexed_db

BUG=457697

Review URL: https://codereview.chromium.org/1146473002

Cr-Commit-Position: refs/heads/master@{#330180}

content/browser/indexed_db/indexed_db_index_writer.cc

@@ -160,7 +160,7 @@ bool MakeIndexWriters(
     if (!can_add_keys)
       return true;
 
-    index_writers->push_back(index_writer.release());
+    index_writers->push_back(index_writer.Pass());
   }
 
   *completed = true;