Makes content handlers see requestor url

Makes content handlers see requestor url

Prior to this fix the incoming connection to the content handler saw
an empty requesting url. This change makes the requesting url
correspond to the url of the first app connecting to the content
handler.

BUG=none
TEST=covered by test
R=ben@chromium.org

Committed: https://crrev.com/57439937b14ad4362ab4dde3f828b7017f4aad8d
Cr-Commit-Position: refs/heads/master@{#329441}

[Ben Goodger (Google), 2015-05-12 17:57:51]

lgtm

[sky, 2015-05-12 18:02:30]

The CQ bit was checked by sky@chromium.org

[sky, 2015-05-12 18:02:30]

The patchset sent to the CQ was uploaded after l-g-t-m from ben@chromium.org
Link to the patchset: https://codereview.chromium.org/1130353005/#ps20001
(title: "merge to trunk")

[commit-bot: I haz the power, 2015-05-12 18:03:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1130353005/20001

[commit-bot: I haz the power, 2015-05-12 18:08:16]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-12 18:08:58]

Patchset 2 (id:??) landed as
https://crrev.com/57439937b14ad4362ab4dde3f828b7017f4aad8d
Cr-Commit-Position: refs/heads/master@{#329441}