GitLab

This also fixes a number of issues I saw when testing Netflix:
-fix http status header not reaching plugin
-send a Content-Type header if one isn't specified by the plugin for POSTs
-null check info->headers, needed for data: URLs

This doesn't support responding to 200s after a byte-range request. I'm gathering stats now to see how often this happens.

BUG=286074
R=ananta@chromium.org, jschuh@chromium.org

Review URL: https://codereview.chromium.org/23830007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@223483 0039d316-1c4b-4281-b951-d872f2087c98