Fix uninitialized memory error in CastTransport.

Fix uninitialized memory error in CastTransport.
Reenable Valgrind runs for CastTransport unit tests.

R=miu,oshima
BUG=418767
TBR=wez@chromium.org

Committed: https://crrev.com/30c32fdc78a8d4e00a8aeec5015a674e64e36195
Cr-Commit-Position: refs/heads/master@{#297483}

[Kevin M, 2014-09-30 00:23:37]

kmarshall@chromium.org changed reviewers:
+ oshima@chromium.org

[oshima, 2014-09-30 00:38:37]

lgtm

[miu, 2014-09-30 03:39:30]

The CQ bit was checked by miu@chromium.org

[miu, 2014-09-30 03:39:30]

lgtm

[commit-bot: I haz the power, 2014-09-30 03:44:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/598333003/20001

[commit-bot: I haz the power, 2014-09-30 03:52:48]

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

[commit-bot: I haz the power, 2014-09-30 03:52:49]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Kevin M, 2014-09-30 16:55:24]

kmarshall@chromium.org changed reviewers:
+ mfoltz@chromium.org, wez@chromium.org

[Kevin M, 2014-09-30 16:56:19]

Need a LGTM from wez@ or mfoltz@.

We should probably get a third OWNER registered for this directory since munjal@
is gone.

[Kevin M, 2014-09-30 18:34:05]

The CQ bit was checked by kmarshall@chromium.org

[commit-bot: I haz the power, 2014-09-30 18:36:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/598333003/20001

[commit-bot: I haz the power, 2014-09-30 19:44:03]

Committed patchset #2 (id:20001) as e880ad2e73ccf9af839adde5a88494d004e148fa

[commit-bot: I haz the power, 2014-09-30 19:45:19]

Patchset 2 (id:??) landed as
https://crrev.com/30c32fdc78a8d4e00a8aeec5015a674e64e36195
Cr-Commit-Position: refs/heads/master@{#297483}

[Wez, 2014-09-30 21:45:22]

lgtm