Set frame liveness before calling RenderFrameCreated/RenderFrameDeleted.

Set frame liveness before calling RenderFrameCreated/RenderFrameDeleted.

In the FrameTree unittests, illustrate the liveness of frames in the ASCII
dumps. Update some tests so that children aren't born to dead parents.

BUG=474231
Committed: https://crrev.com/ad74a7e371149624d91f96cf662f70af6d18787f
Cr-Commit-Position: refs/heads/master@{#325508}

[ncarter (slow), 2015-04-15 21:59:35]

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

[ncarter (slow), 2015-04-15 21:59:35]

Nasko: let me know what you think about this.  This shouldn't affect existing
clients as far as I can see, but ought to make it safe to call functions like
RenderFrameDevToolsAgentHost::AppendAgentHostForFrameIfApplicable from an impl
of WCO::RenderFrameCreated or WCO::RenderFrameDeleted.

But really, I mostly want this for testing -- it's a preamble to my fix for
474231

[nasko, 2015-04-15 22:03:24]

LGTM

[ncarter (slow), 2015-04-16 19:43:25]

The CQ bit was checked by nick@chromium.org

[commit-bot: I haz the power, 2015-04-16 19:43:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1070553005/20001

[commit-bot: I haz the power, 2015-04-16 20:44:47]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-04-16 20:45:40]

Patchset 2 (id:??) landed as
https://crrev.com/ad74a7e371149624d91f96cf662f70af6d18787f
Cr-Commit-Position: refs/heads/master@{#325508}

[johnme, 2015-04-17 14:03:25]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1086613003/ by johnme@chromium.org.

The reason for reverting is: Tentative revert to try to fix
BrowserTest.WindowOpenClose, which is consistently failing on chromium.webkit
Mac10.6 Tests and Mac10.8 Tests.

It times out during
ui_test_utils::NavigateToURLWithDispositionBlockUntilNavigationsComplete and
gets killed whilst waiting for the navigations.

It started failing between
https://build.chromium.org/p/chromium.webkit/builders/Mac10.8%20Tests/builds/474
and
https://build.chromium.org/p/chromium.webkit/builders/Mac10.6%20Tests/builds/...,
so the blamelists are:

Chromium:
https://chromium.googlesource.com/chromium/src.git/+log/96626920573e30a2cd020...

Blink:
https://chromium.googlesource.com/chromium/blink/+log/7f9db67d6a96399f8e4eae4...

This is the only patch that seems at all relevant from amongst those....