Enable the extended filter mode AEC on platforms with known echo issues.

BUG=b/10305369
TESTED=Verified the extended filter mode gets enabled in apprtc.

Review URL: https://codereview.chromium.org/24495007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225435 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225435