Revert "Crash intentionally when requestTiles with invalid key."

This reverts commit 81be6ff273388c5fba75942d2c0ed58e7becb610.

We don't get any reports of crash related to this. So revert this.

BUG: 17401299
BUG: 17369933

Change-Id: I051d82f0aebda4bd148109d658597e0756c9befb
3 files changed