MediaStream API: Deleting RTCPeerConnectionHandler
Removing the unnecessary bridging class RTCPeerConnectionHandler as part of
the effort to get rid of Source/core/platform/mediastream/

Review URL: https://codereview.chromium.org/145553003

git-svn-id: svn://svn.chromium.org/blink/trunk@165669 bbb929c8-8fbe-4397-9dbb-9b2b20218538