Mojo: Add a RawChannel::EnqueueMessage() that can be overridden by subclasses.

mojo/system/raw_channel_posix.cc

Index: mojo/system/raw_channel_posix.cc
diff --git a/mojo/system/raw_channel_posix.cc b/mojo/system/raw_channel_posix.cc
index ecacd29778a27ed899749d896c2155a635f11205..cc6324d547785faf3a93fe498fa85c7671061c4e 100644
--- a/mojo/system/raw_channel_posix.cc
+++ b/mojo/system/raw_channel_posix.cc
@@ -41,6 +41,10 @@ class RawChannelPosix : public RawChannel,
 
  private:
   // |RawChannel| protected methods:
+  // Actually override |EnqueueMessageNoLock()| so that we can send multiple
+  // messages with FDs if necessary.
+  virtual void EnqueueMessageNoLock(
+      scoped_ptr<MessageInTransit> message) OVERRIDE;
   virtual IOResult Read(size_t* bytes_read) OVERRIDE;
   virtual IOResult ScheduleRead() OVERRIDE;
   virtual embedder::ScopedPlatformHandleVectorPtr GetReadPlatformHandles(
@@ -112,6 +116,13 @@ size_t RawChannelPosix::GetSerializedPlatformHandleSize() const {
   return 0;
 }
 
+void RawChannelPosix::EnqueueMessageNoLock(
+    scoped_ptr<MessageInTransit> message) {
+  // TODO(vtl): Split any message with too many platform handles into multiple
+  // messages.
+  RawChannel::EnqueueMessageNoLock(message.Pass());
+}
+
 RawChannel::IOResult RawChannelPosix::Read(size_t* bytes_read) {
   DCHECK_EQ(base::MessageLoop::current(), message_loop_for_io());
   DCHECK(!pending_read_);