SitePerProcessBrowserTest: make some tests to use cross_site_iframe_factory

SitePerProcessBrowserTest: make some tests to use cross_site_iframe_factory

/cross_site_iframe_factory.html?a(a,a(a,a(a))) gives a page that
has the same frame structure as site_per_process_main.html.

Add ids to iframe elements so that they work with NavigateIframeToURL

Re-enable SitePerProcessBrowserTest.NavigateRemoteFrameToBlankAndDataURLs (which does not fail locally for me)

BUG=515672, 465722
Committed: https://crrev.com/4e68f5259e6ed9747bbeec9e4f5dd3767575e949
Cr-Commit-Position: refs/heads/master@{#346222}

[ncarter (slow), 2015-08-27 19:28:50]

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

[ncarter (slow), 2015-08-27 19:28:51]

Charlie: Please have a look. The main motivation of this is to get some working
examples of the cross_site_iframe_factory.html into the codebase, to serve as
templates for other tests.

[Charlie Reis, 2015-08-27 21:14:48]

I like it.  LGTM.

https://codereview.chromium.org/1320023003/diff/1/content/browser/site_per_pr...
File content/browser/site_per_process_browsertest.cc (left):

https://codereview.chromium.org/1320023003/diff/1/content/browser/site_per_pr...
content/browser/site_per_process_browsertest.cc:1199: StartFrameAtDataURL();
Nice.  I'm not sure if the motivation for this method (the whole waiting for
first navigation in a subframe thing) has been resolved, but the factory page
lets you start out in the right state.  In that sense, the only call site of
StartFrameAtDataURL isn't needed anymore, so I'm fine with killing the function.

https://codereview.chromium.org/1320023003/diff/1/content/browser/site_per_pr...
File content/browser/site_per_process_browsertest.cc (right):

https://codereview.chromium.org/1320023003/diff/1/content/browser/site_per_pr...
content/browser/site_per_process_browsertest.cc:662:
NavigateRemoteFrameToBlankAndDataURLs) {
Sure, we can give re-enabling this a try to see if it works now.

[ncarter (slow), 2015-08-28 19:12:43]

The CQ bit was checked by nick@chromium.org

[commit-bot: I haz the power, 2015-08-28 19:13:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1320023003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1320023003/1

[commit-bot: I haz the power, 2015-08-28 20:17:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-28 20:18:07]

Patchset 1 (id:??) landed as
https://crrev.com/4e68f5259e6ed9747bbeec9e4f5dd3767575e949
Cr-Commit-Position: refs/heads/master@{#346222}