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

services/shell/public/cpp/interface_provider.h

Index: services/shell/public/cpp/interface_provider.h
diff --git a/services/shell/public/cpp/interface_provider.h b/services/shell/public/cpp/interface_provider.h
index 865ab8bd5cdcdbcf3e4b3a85def271adc1d96ae6..fe6930e3f825d8a262ca4b4ed20cb13795958c95 100644
--- a/services/shell/public/cpp/interface_provider.h
+++ b/services/shell/public/cpp/interface_provider.h
@@ -18,8 +18,6 @@
 // Connection.
 class InterfaceProvider {
  public:
-  using ForwardCallback = base::Callback<void(const mojo::String&,
-                                              mojo::ScopedMessagePipeHandle)>;
   class TestApi {
    public:
     explicit TestApi(InterfaceProvider* provider) : provider_(provider) {}
@@ -43,16 +41,7 @@
   InterfaceProvider();
   ~InterfaceProvider();
 
-  // Binds this InterfaceProvider to an actual mojom::InterfaceProvider pipe.
-  // It is an error to call this on a forwarding InterfaceProvider, i.e. this
-  // call is exclusive to Forward().
   void Bind(mojom::InterfaceProviderPtr interface_provider);
-
-  // Sets this InterfaceProvider to forward all GetInterface() requests to
-  // |callback|. It is an error to call this on a bound InterfaceProvider, i.e.
-  // this call is exclusive to Bind(). In addition, and unlike Bind(), this MUST
-  // be called before any calls to GetInterface() are made.
-  void Forward(const ForwardCallback& callback);
 
   // Returns a raw pointer to the remote InterfaceProvider.
   mojom::InterfaceProvider* get() { return interface_provider_.get(); }
@@ -94,10 +83,6 @@
   mojom::InterfaceProviderPtr interface_provider_;
   mojom::InterfaceProviderRequest pending_request_;
 
-  // A callback to receive all GetInterface() requests in lieu of the
-  // InterfaceProvider pipe.
-  ForwardCallback forward_callback_;
-
   base::WeakPtrFactory<InterfaceProvider> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InterfaceProvider);