Make sure setupDataChannel resend data if the channel is unreliable.
Re-enable the test WebRtcBrowserTest::CanSetupLegacyCall on Windows.

BUG=350388, 235089
R=phoglund@chromium.org, tommi@chromium.org

Review URL: https://codereview.chromium.org/194703003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256475 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256475