search work

Add a way to go from a message id to a thread id.

Change-Id: I3362155bdb07d7ccf50d3fd3f567a4a7b5c6faf2
Stop using private APIs that are going away.

Change-Id: I2e6ac42f577041aec889fa41c9d923b0f4657957
Merge commit '0ebbb48f9f83ad65d738d1910a38e4fbdb920ac7' into HEAD

* commit '0ebbb48f9f83ad65d738d1910a38e4fbdb920ac7':
  Stop using private APIs that are going away.
  search work