linux (and some posix): multiprocess plugins compiling.

chrome/common/child_process_host.h

Index: chrome/common/child_process_host.h
diff --git a/chrome/common/child_process_host.h b/chrome/common/child_process_host.h
index d4d2dd914457c068b8f683677c15fe87984661e7..5a49a4419a8bdc43ce84c9130a3ff6e5a44ceadb 100644
--- a/chrome/common/child_process_host.h
+++ b/chrome/common/child_process_host.h
@@ -74,6 +74,8 @@ class ChildProcessHost : public ResourceDispatcherHost::Receiver,
   bool opening_channel() { return opening_channel_; }
   const std::wstring& channel_id() { return channel_id_; }
 
+  const IPC::Channel& channel() const { return *channel_; }
+
  private:
   // Sends the given notification to the notification service on the UI thread.
   void Notify(NotificationType type);