Switch ControlGroup and MatchCompleteDummy to XHR PUT from alert.

Switch ControlGroup and MatchCompleteDummy to XHR PUT from alert.

If the test exits before the navigation completes, the alert may cause
difficulties. Use PUTs instead for an abort which does not trigger UI or
anything.  Re-enable the tests on OS X as that was probably the cause for the
flake.

BUG=142535, 142912
TEST=PrerenderBrowserTest.ControlGroup,
     PrerenderBrowserTest.MatchCompleteDummy

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=244095

[davidben, 2014-01-09 21:47:51]

Ran into this as part of other test fixup work I'm doing. It occurred to me that
this is probably the cause of the flake, so I'm speculatively re-enabling them.
We'll see if they need to get disabled again. (What else could be OS-specific
about these tests? They're pretty tame-looking.)

[mmenke, 2014-01-09 21:51:11]

On 2014/01/09 21:47:51, David Benjamin wrote:
> Ran into this as part of other test fixup work I'm doing. It occurred to me
that
> this is probably the cause of the flake, so I'm speculatively re-enabling
them.
> We'll see if they need to get disabled again. (What else could be OS-specific
> about these tests? They're pretty tame-looking.)

LGTM

[commit-bot: I haz the power, 2014-01-09 22:41:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/davidben@chromium.org/132643002/1

[commit-bot: I haz the power, 2014-01-10 05:08:08]

Change committed as 244095