OOPIF: Fix CapturePageInfo to only operate on local main frames.

OOPIF: Fix CapturePageInfo to only operate on local main frames.

This logic will need to move to the browser process to capture text
from frames that live in other processes.

BUG=346764
TEST=Navigate in an out-of-process iframe and wait 10 seconds.

Committed: https://crrev.com/ec6b51a9acf58ca21219c28a51e85d98f6f873dd
Cr-Commit-Position: refs/heads/master@{#299138}

[Charlie Reis, 2014-10-10 16:04:54]

creis@chromium.org changed reviewers:
+ nasko@chromium.org

[Charlie Reis, 2014-10-10 16:04:55]

Nasko: This gets us past the page info crash, since it's trying to walk the
frame tree to capture it as text.  The full fix will involve moving this logic
to the browser process and stitching together text for each frame.

[Charlie Reis, 2014-10-10 17:08:11]

creis@chromium.org changed reviewers:
+ alexmos@chromium.org
- nasko@chromium.org

[Charlie Reis, 2014-10-10 17:40:32]

Alex, can you review since Nasko is out today?

[alexmos, 2014-10-10 17:42:33]

LGTM

[Charlie Reis, 2014-10-10 17:44:14]

creis@chromium.org changed reviewers:
+ sky@chromium.org

[Charlie Reis, 2014-10-10 17:45:38]

[+sky]

Thanks!  Scott, can you take a look for chrome/ owner's approval?  This gets
link click navigations to work in out-of-process iframes, until we refactor this
logic.  Shouldn't affect things unless --site-per-process is passed.

[sky, 2014-10-10 17:59:57]

LGTM

[Charlie Reis, 2014-10-10 18:04:35]

The CQ bit was checked by creis@chromium.org

[commit-bot: I haz the power, 2014-10-10 18:05:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/645803002/1

[commit-bot: I haz the power, 2014-10-10 18:17:11]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-10 18:18:06]

Patchset 1 (id:??) landed as
https://crrev.com/ec6b51a9acf58ca21219c28a51e85d98f6f873dd
Cr-Commit-Position: refs/heads/master@{#299138}