Make AudioParameters a class instead of a struct

Also collapses some long parameter lists into AudioParameters and moves some
of the hardcoded values (e.g. 16 bit audio in AudioDevice) to more appropriate
locations.

BUG=115902
TEST=manually testing everything works out

Review URL: https://chromiumcodereview.appspot.com/9655018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@128054 0039d316-1c4b-4281-b951-d872f2087c98
75 files changed