Fix worker WebSocket crash caused by dereferencing weak pointer

Fix worker WebSocket crash caused by dereferencing weak pointer

WorkerWebSocketChannel::Peer::m_bridge is bound to workerGlobalScopeDidError
as |bridge|. Because it is a CrossThreadWeakPersistent, it's possible that
|m_bridge| is not null when bound but |bridge| is null when called. This CL
adds null pointer checks to avoid a crash.

BUG=625649
Review-Url: https://codereview.chromium.org/2123703002
Cr-Commit-Position: refs/heads/master@{#403744}
(cherry picked from commit bb4da95f6202839ccf81445d1d0ff2cb9c07118b)

Committed: https://chromium.googlesource.com/chromium/src/+/edd6a8a2e036ac614a5e62d64ce737fbd968e852

[yhirano, 2016-07-06 10:25:04]

Description was changed from

==========
Fix worker WebSocket crash caused by dereferencing weak pointer

WorkerWebSocketChannel::Peer::m_bridge is bound to workerGlobalScopeDidError
as |bridge|. Because it is a CrossThreadWeakPersistent, it's possible that
|m_bridge| is not null when bound but |bridge| is null when called. This CL
adds null pointer checks to avoid a crash.

BUG=625649

Review-Url: https://codereview.chromium.org/2123703002
Cr-Commit-Position: refs/heads/master@{#403744}
(cherry picked from commit bb4da95f6202839ccf81445d1d0ff2cb9c07118b)
==========

to

==========
Fix worker WebSocket crash caused by dereferencing weak pointer

WorkerWebSocketChannel::Peer::m_bridge is bound to workerGlobalScopeDidError
as |bridge|. Because it is a CrossThreadWeakPersistent, it's possible that
|m_bridge| is not null when bound but |bridge| is null when called. This CL
adds null pointer checks to avoid a crash.

BUG=625649

Review-Url: https://codereview.chromium.org/2123703002
Cr-Commit-Position: refs/heads/master@{#403744}
(cherry picked from commit bb4da95f6202839ccf81445d1d0ff2cb9c07118b)

Committed:
https://chromium.googlesource.com/chromium/src/+/edd6a8a2e036ac614a5e62d64ce7...
==========

[yhirano, 2016-07-06 10:25:07]

Committed patchset #1 (id:1) manually as
edd6a8a2e036ac614a5e62d64ce737fbd968e852.