Override AudioManager::MakeAudioInputStream() in NullAudioManager.
Override AudioManager::MakeAudioInputStream() in NullAudioManager.

BUG=72577
TEST=None

Review URL: http://codereview.chromium.org/6487008

git-svn-id: http://src.chromium.org/svn/trunk/src@74492 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 38fc35677989ce4f170bc3aab0021b0e98febc05
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