Revert 256709 "Relanding https://codereview.chromium.org/1593530..."
This broke Chrome official since it has global construction code (see files added in libjingle.gyp)

> Relanding https://codereview.chromium.org/159353002/ after some minor modifications. Fixing tests mainly.
> 
> It got reverted due to ASAN failures in http://build.chromium.org/p/chromium.memory/buildstatus?builder=Linux%20ASan%2BLSan%20Tests%20%282%29&number=396
> 
> Original CL description:
> This CL adds methods to manipulate RTP header extension, particularly
> AbsoulteSendTime extension. If there is matching extension ID present
> in RTP packet, we will update with the current time.
> 
> TBR=sergeyu@chromium.org
> 
> Review URL: https://codereview.chromium.org/197713005

TBR=mallinath@chromium.org

Review URL: https://codereview.chromium.org/199593002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256945 0039d316-1c4b-4281-b951-d872f2087c98
Updating XTBs based on .GRDs from branch 1847

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256946 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256946