Eliminate the dependence of tts extension API form tts_controller.cc

This is the first patch to move TTS implementation from browser layer
to content. To move TTS to conent, the direct dependence of browser
compoent should be eliminated from TTS classes first.

BUG=347045
[email protected], [email protected], [email protected]

Review URL: https://codereview.chromium.org/374243004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282813 0039d316-1c4b-4281-b951-d872f2087c98
6 files changed