PlzNavigate: properly set file access permissions on the RFH

PlzNavigate: properly set file access permissions on the RFH

This CL gives appropriate permissions to the RenderFrameHost on
NavigationCommit. This allows to run browser tests backed by javascript files
on disk with PlzNavigate enabled.

BUG=475027
Committed: https://crrev.com/3d638b14a085318d039cff23acfb5692ae6f7150
Cr-Commit-Position: refs/heads/master@{#327328}

[clamy, 2015-04-27 17:11:42]

clamy@chromium.org changed reviewers:
+ carlosk@chromium.org, fdegans@chromium.org, nasko@chromium.org

[clamy, 2015-04-27 17:12:22]

@nasko: PTAL
@carlosk, fdegans: FYI

Note that this fixes _a lot_ of browser tests :).

[nasko, 2015-04-28 17:02:03]

LGTM

[clamy, 2015-04-28 17:26:02]

The CQ bit was checked by clamy@chromium.org

[commit-bot: I haz the power, 2015-04-28 17:26:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1103253003/1

[commit-bot: I haz the power, 2015-04-28 18:15:04]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-28 18:16:45]

Patchset 1 (id:??) landed as
https://crrev.com/3d638b14a085318d039cff23acfb5692ae6f7150
Cr-Commit-Position: refs/heads/master@{#327328}