Add null check for frame when creating WebCore::Performance.

Add null check for frame when creating WebCore::Performance.

This regression was introduced in r168256. The previous behavior
depended on whether Frame had already been garbage collected after being
removed from the DOM. If it had not been garbage collected yet, then it
would return a Performance object, but if it had, then it would return
null.

This patch adds the now-necessary check that frame is non-null and makes
the behavior consistent whether or not the underlying Frame object has
already been garbage collected, which makes Firefox's behavior.

BUG=350978
R=abarth@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169467

[dcheng, 2014-03-18 03:56:36]

I haven't actually verified that Firefox does this, but I plan on doing so when
I get in tomorrow morning... I need to figure out how to force GC in Firefox for
testing purposes for this as well.

I've also removed the special cases added for the Battery Status API--I think
that we should try to make sure new code is consistent in the situation of a
detached frame...

[abarth-chromium, 2014-03-18 15:30:52]

lgtm

[commit-bot: I haz the power, 2014-03-18 15:30:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dcheng@chromium.org/203053002/1

[commit-bot: I haz the power, 2014-03-18 16:00:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-18 16:00:56]

Try jobs failed on following builders:
  tryserver.blink on mac_blink_rel

[Srini, 2014-03-18 16:09:53]

On 2014/03/18 03:56:36, dcheng wrote:
> I haven't actually verified that Firefox does this, but I plan on doing so
when
> I get in tomorrow morning... I need to figure out how to force GC in Firefox
for
> testing purposes for this as well.
> 
> I've also removed the special cases added for the Battery Status API--I think
> that we should try to make sure new code is consistent in the situation of a
> detached frame...

You only updated the test expectation for non-mac platforms. You need to either
update test expected results for Mac or use NeedRebaseLine [1] to generate
results for Mac for the below cases. 

LayoutTests/platform/mac/fast/dom/Window/property-access-on-cached-properties-after-frame-navigated-expected.txt
LayoutTests/platform/mac/fast/dom/Window/property-access-on-cached-properties-after-frame-removed-expected.txt
LayoutTests/platform/mac/fast/dom/Window/property-access-on-cached-window-after-frame-navigated-expected.txt
LayoutTests/platform/mac/fast/dom/Window/property-access-on-cached-window-after-frame-removed-expected.txt

[1] -
http://www.chromium.org/developers/testing/webkit-layout-tests/testexpectations

[dcheng, 2014-03-18 18:46:05]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2014-03-18 18:46:18]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dcheng@chromium.org/203053002/20001

[commit-bot: I haz the power, 2014-03-18 18:49:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-18 18:49:53]

Try jobs failed on following builders:
  tryserver.blink on linux_blink_dbg

[dcheng, 2014-03-18 19:55:29]

Committed patchset #2 manually as r169467 (presubmit successful).