Allowed the users to set the volume above 100% when AGC is enabled, in this case AGC can gradually scale down the volume instead of jumping to 100% immediately. Reduced the flakiness of the volume tests in linux. Review URL: https://webrtc-codereview.appspot.com/387011 git-svn-id: http://webrtc.googlecode.com/svn/trunk@1706 4adac7df-926f-26a2-2b94-8c16560cd09d