Revert 244590 "Remove VideoRenderer::NaturalSizeChangedCB."

> Remove VideoRenderer::NaturalSizeChangedCB.
> 
> Instead WebMediaPlayerImpl detects frame size changes and bypasses the previous plumbing through Pipeline.
> 
> BUG=319000
> 
> Review URL: https://codereview.chromium.org/113233004

TBR=scherkus@chromium.org

Review URL: https://codereview.chromium.org/137733002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244633 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244633