OOPIF: Create subframe FrameNavigationEntries for AUTO_SUBFRAME navigations.

OOPIF: Create subframe FrameNavigationEntries for AUTO_SUBFRAME navigations.

Only takes effect in --site-per-process mode.  Just the first phase of
adding frame entries; won't handle nested iframes or history navigations
yet.

BUG=236848
TEST=New unit and browser tests pass in --site-per-process mode.

Committed: https://crrev.com/625a0c7daf175770733234a1ba3a2ebb70e4c107
Cr-Commit-Position: refs/heads/master@{#322088}

[Charlie Reis, 2015-03-24 18:05:11]

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

[Charlie Reis, 2015-03-24 18:05:13]

Ok, time to start filling in the tree of FrameNavigationEntries!  I decided to
start small to just land a bit of the infrastructure at a time, but let me know
if you want me to do a bigger piece here (e.g., more of AddOrUpdateFrameEntry).

I'll add browser tests and update existing unit tests for these CLs.  They'll
only test the subframe entries if --site-per-process is passed, so we'll see it
on our try bot and FYI bots.

Let me know if you have opinions about the interfaces, since it's still early
enough to refine them easily.  I'm toying with whether we can hide TreeNode as a
private detail of NavigationEntry (apart from test code), if I can avoid having
to interact with it in NavigationController.

https://codereview.chromium.org/1029893002/diff/1/content/browser/frame_host/...
File content/browser/frame_host/navigation_entry_impl.h (right):

https://codereview.chromium.org/1029893002/diff/1/content/browser/frame_host/...
content/browser/frame_host/navigation_entry_impl.h:149: SiteInstanceImpl*
site_instance,
I'm not thrilled with having to take all of the FrameNavigationEntry constructor
parameters here, but some cases need to create a new one and some cases need to
update an existing one.  We may also need to create the TreeNode if this is the
first time we're hearing from a frame.  In that sense, this method signature
lets NavigationEntryImpl take care of all the details.

[Avi (use Gerrit), 2015-03-24 21:02:05]

This LGTM. You're sneaking in a few new tests for me to pass in my other CL, but
I'll cope. :)

[Charlie Reis, 2015-03-24 21:37:28]

The CQ bit was checked by creis@chromium.org

[commit-bot: I haz the power, 2015-03-24 21:39:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1029893002/1

[commit-bot: I haz the power, 2015-03-24 23:17:24]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-24 23:18:04]

Patchset 1 (id:??) landed as
https://crrev.com/625a0c7daf175770733234a1ba3a2ebb70e4c107
Cr-Commit-Position: refs/heads/master@{#322088}