Fix video capture bug in a utility function, GetPin, and how it was being used.

Fix video capture bug in a utility function, GetPin, and how it was being used.
This function could set an outgoing pointer to an already-released COM object, and then (correctly) return an error.
At the call sites though, the return value was not being checked, but instead the pointer was checked.
The worst part (and this is really the bug) about this was that if the pointer was valid on return, we would always call Release() on it, and that caused us to attempt to release an already-released object.

BUG=354027
TBR=mcasas

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=260467

[tommi (sloooow) - chröme, 2014-03-30 15:42:18]

Change GetPin to just return the object since the return value wasn't being used

[tommi (sloooow) - chröme, 2014-03-30 15:48:31]

TBR-ing and sending to the cq since it fixes a frequent crash.

[tommi (sloooow) - chröme, 2014-03-30 15:48:35]

The CQ bit was checked by tommi@chromium.org

[commit-bot: I haz the power, 2014-03-30 15:48:51]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tommi@chromium.org/218673002/10001

[commit-bot: I haz the power, 2014-03-30 20:51:11]

Change committed as 260467

[DaleCurtis, 2014-03-31 17:21:18]

Good catch, I wonder if other ScopedComPtr instances have similar failure modes.