content: Add valid handle check to ChildDiscardableSharedMemoryManager::AllocateLockedDiscardableSh…

content: Add valid handle check to ChildDiscardableSharedMemoryManager::AllocateLockedDiscardableSharedMemory.

This check allows us to distinguish between allocation failure
on the browser side and failure to map the memory in the child
process.

BUG=460995
Committed: https://crrev.com/527e2da9822a168f55dcf23fb51a28202f90879a
Cr-Commit-Position: refs/heads/master@{#317746}

[reveman, 2015-02-23 19:43:30]

reveman@chromium.org changed reviewers:
+ avi@chromium.org

[Avi (use Gerrit), 2015-02-23 19:47:59]

lgtm

ok

[reveman, 2015-02-24 02:21:43]

The CQ bit was checked by reveman@chromium.org

[commit-bot: I haz the power, 2015-02-24 02:22:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/939343003/1

[commit-bot: I haz the power, 2015-02-24 02:43:48]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-24 02:44:34]

Patchset 1 (id:??) landed as
https://crrev.com/527e2da9822a168f55dcf23fb51a28202f90879a
Cr-Commit-Position: refs/heads/master@{#317746}