Fix thread safety issue in AudioMessageFilter.  IPC::Channel can only be used on the IO thread. Review URL: http://codereview.chromium.org/600002
Fix thread safety issue in AudioMessageFilter.  IPC::Channel can only be used on the IO thread.
Review URL: http://codereview.chromium.org/600002

git-svn-id: http://src.chromium.org/svn/trunk/src@38454 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: b5b3a5b4693ee3cbc7c0cf4bb44104c68806c6a2
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser