Convert plugin and GPU process to brokered handle duplication.

BUG=119250
Review URL: https://chromiumcodereview.appspot.com/9958034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@132303 0039d316-1c4b-4281-b951-d872f2087c98
bool PluginChannel::Init(base::MessageLoopProxy* ipc_message_loop,
                         bool create_pipe_now,
                         base::WaitableEvent* shutdown_event) {
  if (!NPChannelBase::Init(ipc_message_loop, create_pipe_now, shutdown_event))
    return false;

  channel_->AddFilter(filter_.get());
  return true;
}

bool PluginChannel::Init(base::MessageLoopProxy* ipc_message_loop,
                         bool create_pipe_now,
                         base::WaitableEvent* shutdown_event) {
  if (!NPChannelBase::Init(ipc_message_loop, create_pipe_now, shutdown_event))
    return false;

  channel_->AddFilter(filter_.get());
  return true;
}
