[TTS] Refactor the Component to use layered dirs.

Refactors the Contextual Search Component to use the layered directory
layout recommended for iOS support.  This CL splits the top-level
directories into /core and /content.  A few files that are clearly
not dependent on any content have been moved to /core/, and everything
else is moved to /content/.  There will be some additional /core/ files
landing soon.

This CL doesn't change any logic or functionality, it just moves source
files.

BUG=646019,825428

Change-Id: Ia4bf5cdecaabf7d9515b2d4fca855db29b1c4b1c
Reviewed-on: https://chromium-review.googlesource.com/1173019
Reviewed-by: Scott Violet <[email protected]>
Reviewed-by: Theresa <[email protected]>
Reviewed-by: Dominick Ng <[email protected]>
Commit-Queue: Donn Denman <[email protected]>
Cr-Commit-Position: refs/heads/master@{#584566}
29 files changed