Fix a chrome browser crash observed in chrome frame reliability test runs. Th...

Fix a chrome browser crash observed in chrome frame reliability test runs. The crash occurs
when the automation channel is being torn down and a Send on the channel is attempted after
the channel has been closed. 

We crash while dereferencing a NULL channel pointer in OnSendMessage task.

Fix is to add a check for the same.

Fixes bug http://code.google.com/p/chromium/issues/detail?can=2&q=54115

Bug=54115
Test=Covered by new ipc sync channel test.


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=58408

[jam, 2010-09-02 17:55:39]

http://codereview.chromium.org/3337004/diff/9001/4002
File ipc/ipc_channel_proxy.cc (right):

http://codereview.chromium.org/3337004/diff/9001/4002#newcode158
ipc/ipc_channel_proxy.cc:158: if (!channel_ || !channel_->Send(message))
do we really want to call OnChannelError in this case?  it seems we should just
drop the message, i.e.

if (!channel) {
  delete message;
  return;
}

[jam, 2010-09-02 19:24:36]

lgtm