Oilpan: consistently use IsGarbageCollectedMixin<> trait.

Oilpan: consistently use IsGarbageCollectedMixin<> trait.

Use blink::IsGarbageCollectedMixin<T> to test if the object
T implements GarbageCollectedMixin. It handles objects that
have multiple GarbageCollectedMixin bases.

With that in place for WebPrivatePtr<>'s LifetimeOf trait,
SpeechRecognition's specialization for it can be retired.

R=haraken
BUG=420515
TBR=tkent

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=191900

[sof, 2015-03-14 06:21:22]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2015-03-14 06:21:22]

please take a look.

[haraken, 2015-03-14 08:35:00]

LGTM

[sof, 2015-03-14 09:18:44]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-03-14 09:18:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1007803004/1

[commit-bot: I haz the power, 2015-03-14 09:35:55]

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

[commit-bot: I haz the power, 2015-03-14 09:35:56]

Try jobs failed on following builders:
  blink_presubmit on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/blink_presubmit/builds/2...)

[sof, 2015-03-14 09:42:48]

sigbjornf@opera.com changed reviewers:
+ tkent@chromium.org

[sof, 2015-03-14 09:42:48]

tkent@: please take a look at the WebPrivatePtr<> change? tia.

[sof, 2015-03-16 06:15:51]

TBRing the public/platform/ change.

[sof, 2015-03-16 06:15:56]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-03-16 06:16:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1007803004/1

[tkent, 2015-03-16 06:41:10]

lgtm

[commit-bot: I haz the power, 2015-03-16 09:12:11]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=191900