Set up a NaCl load status callback to start replacing "start_module".

components/nacl/renderer/trusted_plugin_channel.h

Index: components/nacl/renderer/trusted_plugin_channel.h
diff --git a/components/nacl/renderer/trusted_plugin_channel.h b/components/nacl/renderer/trusted_plugin_channel.h
index efeb5e8fe988834df922756ebb6924feef60d6ad..9d87d21fb64b64e8d0b711179626dc46b338d1d1 100644
--- a/components/nacl/renderer/trusted_plugin_channel.h
+++ b/components/nacl/renderer/trusted_plugin_channel.h
@@ -28,7 +28,7 @@ class TrustedPluginChannel : public IPC::Listener {
   TrustedPluginChannel(NexeLoadManager* nexe_load_manager,
                        const IPC::ChannelHandle& handle,
                        base::WaitableEvent* shutdown_event,
-                       bool report_exit_status);
+                       bool main_service_runtime);

[Mark Seaborn, 2015/04/17 23:30:58]

This name is rather cryptic and its meaning isn't commented in the existing
code.  Maybe you could use a more descriptive name such as "is_helper_nexe" or
"is_pnacl_translator", and invert the variable?

[jvoung (off chromium), 2015/04/18 01:00:46]

Done.

   ~TrustedPluginChannel() override;
 
   bool Send(IPC::Message* message);
@@ -38,13 +38,14 @@ class TrustedPluginChannel : public IPC::Listener {
   void OnChannelError() override;
 
   void OnReportExitStatus(int exit_status);
+  void OnReportLoadStatus(int load_status);
 
  private:
   // Non-owning pointer. This is safe because the TrustedPluginChannel is owned
   // by the NexeLoadManager pointed to here.
   NexeLoadManager* nexe_load_manager_;
   scoped_ptr<IPC::SyncChannel> channel_;
-  bool report_exit_status_;
+  bool main_service_runtime_;
 
   DISALLOW_COPY_AND_ASSIGN(TrustedPluginChannel);
 };