Refactor how VideoCapturerAndroid delivers frames and is stopped.
With this cl, video buffers are now allocated using direct buffers.
These buffers are guaranteed to live as long as the capturer is running.
We can now post frames in c++ from the Java thread to the  c++ worker thread and let c++ post the buffers back when it has finished
processing them.

This cl also reverts back to make Stop asynchronouse so that it is guaranteed that the c++ worker thread is not used and no frames are delivered to VideoCapturerAndroid after Stop completes.

BUG=4318
TESTED= On a N5, N6, N9 and Samsung device.
R=glaznev@webrtc.org, magjed@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/43369004

Cr-Commit-Position: refs/heads/master@{#8493}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8493 4adac7df-926f-26a2-2b94-8c16560cd09d
7 files changed