Enable null GeolocationInspectorAgent for out-of-process iframes

Enable null GeolocationInspectorAgent for out-of-process iframes.

We are not yet able to use inspector agents when the top-level frame is
in another process. This patch prevents a crash in that scenario.

BUG=357747
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179052

[kenrb, 2014-07-28 17:43:04]

Eric, can you please look at this small patch? This regressed due to a recent
oilpan-related change, breaking a Chromium CL that I haven't landed yet.

[eseidel, 2014-07-28 17:51:08]

Other than confusion from the member change, lgtm.

https://codereview.chromium.org/422943002/diff/1/Source/modules/geolocation/G...
File Source/modules/geolocation/GeolocationController.cpp (right):

https://codereview.chromium.org/422943002/diff/1/Source/modules/geolocation/G...
Source/modules/geolocation/GeolocationController.cpp:44: ,
m_inspectorAgent(nullptr)
I'm confused why this change is needed?

This is a RawPtrWillBeMember, presumably this code was already zeroing?  Won't
Member zero?

[kenrb, 2014-07-28 18:06:20]

https://codereview.chromium.org/422943002/diff/1/Source/modules/geolocation/G...
File Source/modules/geolocation/GeolocationController.cpp (right):

https://codereview.chromium.org/422943002/diff/1/Source/modules/geolocation/G...
Source/modules/geolocation/GeolocationController.cpp:44: ,
m_inspectorAgent(nullptr)
On 2014/07/28 17:51:08, eseidel wrote:
> I'm confused why this change is needed?
> 
> This is a RawPtrWillBeMember, presumably this code was already zeroing?  Won't
> Member zero?

In release builds yes, but in debug it RawPtr gets the zap value 0x3a3a3a3a. So
testing for zero doesn't work there.

[kenrb, 2014-07-28 18:06:34]

The CQ bit was checked by kenrb@chromium.org

[commit-bot: I haz the power, 2014-07-28 18:07:04]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/kenrb@chromium.org/422943002/1

[eseidel, 2014-07-28 18:09:08]

Woh.  Why is it ever ok to call the RawPtrWillBeMember default constructor then?
 It seems any users of that are using a relatively unsafe c++ pattern of not
initialziaing members in the constructor.

[kenrb, 2014-07-28 18:17:50]

I was surprised by this also. It is the constructor of WTF::RawPtr, which is the
#define of RawPtrWillBeMember unless you build with oilpan enabled.

The explanation is of this anomaly is here:
http://src.chromium.org/viewvc/blink?view=revision&revision=169922

[commit-bot: I haz the power, 2014-07-28 18:44:35]

Change committed as 179052