Revert of Move content's shell connections to the IO thread

content/browser/mojo/mojo_child_connection.h

Index: content/browser/mojo/mojo_child_connection.h
diff --git a/content/browser/mojo/mojo_child_connection.h b/content/browser/mojo/mojo_child_connection.h
index c51f67e40b5e6806baaf60de6f94356b0b85b47e..9ed83da4ae977308fed1604f176ec8eb025917aa 100644
--- a/content/browser/mojo/mojo_child_connection.h
+++ b/content/browser/mojo/mojo_child_connection.h
@@ -9,12 +9,7 @@
 #include <string>
 
 #include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
 #include "base/process/process_handle.h"
-#include "base/sequenced_task_runner.h"
-#include "services/shell/public/cpp/interface_provider.h"
-#include "services/shell/public/cpp/interface_registry.h"
 #include "services/shell/public/interfaces/connector.mojom.h"
 
 #if defined(OS_ANDROID)
@@ -40,16 +35,11 @@
   MojoChildConnection(const std::string& application_name,
                       const std::string& instance_id,
                       const std::string& child_token,
-                      shell::Connector* connector,
-                      scoped_refptr<base::SequencedTaskRunner> io_task_runner);
+                      shell::Connector* connector);
   ~MojoChildConnection();
 
-  shell::InterfaceRegistry* GetInterfaceRegistry() {
-    return &interface_registry_;
-  }
-
-  shell::InterfaceProvider* GetRemoteInterfaces() {
-    return &remote_interfaces_;
+  shell::Connection* connection() const {
+    return connection_.get();
   }
 
   // A token which must be passed to the child process via
@@ -69,23 +59,12 @@
 #endif
 
  private:
-  class IOThreadContext;
-
-  void GetInterface(const mojo::String& interface_name,
-                    mojo::ScopedMessagePipeHandle request_handle);
-
-  scoped_refptr<IOThreadContext> context_;
-
   const std::string service_token_;
-
-  shell::InterfaceRegistry interface_registry_;
-  shell::InterfaceProvider remote_interfaces_;
-
+  std::unique_ptr<shell::Connection> connection_;
+  shell::mojom::PIDReceiverPtr pid_receiver_;
 #if defined(OS_ANDROID)
   std::unique_ptr<ServiceRegistryAndroid> service_registry_android_;
 #endif
-
-  base::WeakPtrFactory<MojoChildConnection> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoChildConnection);
 };