Support cross-process navigations in a single subframe RenderFrameHost.

Support cross-process navigations in a single subframe RenderFrameHost.

This relies on a hack of detecting when a NavigationEntry is for a
subframe RenderFrameHost, even though the navigation occurs in a
top-level RenderViewHost.  It supports cases with at most one frame,
and is only enabled when --site-per-process is used.

BUG=314791
TEST=New process is created for a cross-site iframe with --site-per-process.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=242639

[Charlie Reis, 2013-12-20 23:20:08]

Ok, this one's working and has a test now.  Should be ready for review.

https://codereview.chromium.org/118443008/diff/50001/content/browser/frame_ho...
File content/browser/frame_host/navigation_controller_impl.h (right):

https://codereview.chromium.org/118443008/diff/50001/content/browser/frame_ho...
content/browser/frame_host/navigation_controller_impl.h:139: bool
RendererDidNavigate(RenderViewHost* rvh,
If you want, these changes to NavigationController and
NavigationControllerDelegate can be carved out into their own CL, separate from
the --site-per-process logic.  Ok either way.

https://codereview.chromium.org/118443008/diff/50001/content/browser/web_cont...
File content/browser/web_contents/web_contents_impl.cc (right):

https://codereview.chromium.org/118443008/diff/50001/content/browser/web_cont...
content/browser/web_contents/web_contents_impl.cc:2311: is_main_frame = false;
This eliminates the need for the web_navigation_api.cc change from the draft CL:
https://codereview.chromium.org/30323002/diff/720001/chrome/browser/extension...

[nasko, 2013-12-27 19:34:37]

LGTM

[commit-bot: I haz the power, 2013-12-27 19:35:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/creis@chromium.org/118443008/50001

[commit-bot: I haz the power, 2013-12-27 21:56:25]

Change committed as 242639