Deflake PrerenderBrowserTest.PrerenderClientRedirectInIframe.

Deflake PrerenderBrowserTest.PrerenderClientRedirectInIframe.

What seems to be happening is that the client redirect can
result in starting and stopping the page loading again.  As
a result, we quit the message loop when the second load
finishes as well as the first, which can occur either while
we're waiting for the result of a Javascript function, or
while we're waiting for the navigation to occur.  Either
case will result in a test failure.

BUG=88973
TEST=PrerenderBrowserTest.PrerenderClientRedirectInIframe (And probably PrerenderBrowserTest.PrerenderClientRedirectToHttpsInIframe)

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=102431

[mmenke, 2011-09-22 03:35:44]

Both changes aren't necessary, either one alone should do the trick, but in
retrospect, quitting the message loop multiple times on DidStopLoading just
seems a bad idea.

[cbentzel, 2011-09-22 19:26:32]

LGTM

[commit-bot: I haz the power, 2011-09-22 20:24:58]

CQ is trying tha patch. Follow status at
https://chromium-status.appspot.com/cq/mmenke@chromium.org/7981033/3004

[commit-bot: I haz the power, 2011-09-23 00:02:20]

The commit queue went berserk retrying too often for a
seemingly flaky test. Builder is mac_rel, revision is 102397, job name
was 7981033-3004 (retry) (previous was lost) (previous was lost) (retry).

[commit-bot: I haz the power, 2011-09-23 00:05:49]

CQ is trying tha patch. Follow status at
https://chromium-status.appspot.com/cq/mmenke@chromium.org/7981033/3004

[commit-bot: I haz the power, 2011-09-23 02:37:02]

Change committed as 102431