Allow ChildThreadImpl subclasses to manually start MojoShellConnection

content/child/child_thread_impl.h

Index: content/child/child_thread_impl.h
diff --git a/content/child/child_thread_impl.h b/content/child/child_thread_impl.h
index e4447c9ed1adb41d14e98df097a22df12e15c115..a68a63924d3fdfd99d43f1cb64c0498bf9046169 100644
--- a/content/child/child_thread_impl.h
+++ b/content/child/child_thread_impl.h
@@ -203,9 +203,10 @@ class CONTENT_EXPORT ChildThreadImpl
   // Called when the process refcount is 0.
   void OnProcessFinalRelease();
 
-  // Implemented by subclasses to attach ConnectionFilters to the thread's
-  // shell connection.
-  virtual void AddConnectionFilters(MojoShellConnection* connection);
+  // Called by subclasses to manually start the MojoShellConnection. Must only
+  // be called if ChildThreadImpl::Options::auto_start_mojo_shell_connection
+  // was set to |false| on ChildThreadImpl construction.
+  void StartMojoShellConnection();
 
   virtual bool OnControlMessageReceived(const IPC::Message& msg);
   virtual void OnProcessBackgrounded(bool backgrounded);
@@ -323,6 +324,7 @@ struct ChildThreadImpl::Options {
 
   std::string channel_name;
   bool use_mojo_channel;
+  bool auto_start_mojo_shell_connection;
   scoped_refptr<base::SequencedTaskRunner> browser_process_io_runner;
   std::vector<IPC::MessageFilter*> startup_filters;
   std::string in_process_ipc_token;
@@ -338,6 +340,7 @@ class ChildThreadImpl::Options::Builder {
 
   Builder& InBrowserProcess(const InProcessChildThreadParams& params);
   Builder& UseMojoChannel(bool use_mojo_channel);
+  Builder& AutoStartMojoShellConnection(bool auto_start);
   Builder& WithChannelName(const std::string& channel_name);
   Builder& AddStartupFilter(IPC::MessageFilter* filter);