New tab UI media indicator for recording, tab capture, and audio playback.

Implementation of new tab media indicator designed by the UX team.  This replaces the existing "throbber animation over favicon" indicators with a simpler, less-distracting static icon (right-aligned).

1. Pulled out all existing recording/capture layout, animation, paint code, and graphics.
2. Modified existing audio playback indicator to become a multi-purpose media indicator.
3. Updated visibility precedence logic for media indicator, per discussion in bug.
4. Refactored duplicated code into tab_utils.h/.cc.

Testing: Updated unit tests.  Manual look-and-feel testing to confirm correct behavior and animation transition smoothness on all of: Aura, Win non-Aura, Mac, and GTK.

BUG=290550

Review URL: https://codereview.chromium.org/26922003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228838 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228838