Resubmit 'Refactor the TrayAudio code so that it can be used by other platforms.'

This resubmission fixes a memory leak that was causing ASAN bots to fail.

Original code review: https://codereview.chromium.org/163953007

BUG=227247
R=jennyz@chromium.org
TBR=jamescook, jennyz

Review URL: https://codereview.chromium.org/165393013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252064 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252064