Running the IndexedDB perf (idb_perf) tests in Telemetry

This new test suite name is indexed_db. The tests in the indexeddb
performance_ui_test will be deleted in a subsequent commit.

BUG=237712

Review URL: https://codereview.chromium.org/64753004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235937 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235937