Move content's shell connections to the IO thread

services/shell/public/cpp/interface_provider.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SERVICES_SHELL_PUBLIC_CPP_INTERFACE_PROVIDER_H_
 #define SERVICES_SHELL_PUBLIC_CPP_INTERFACE_PROVIDER_H_
 
 #include "services/shell/public/interfaces/interface_provider.mojom.h"
 
 namespace shell {
 
 // Encapsulates a mojom::InterfaceProviderPtr implemented in a remote
 // application. Provides two main features:
 // - a typesafe GetInterface() method for binding InterfacePtrs.
 // - a testing API that allows local callbacks to be registered that bind
 //   requests for remote interfaces.
 // An instance of this class is used by the GetInterface() methods on
 // Connection.
 class InterfaceProvider {
  public:
+  using ForwardCallback = base::Callback<void(const mojo::String&,
+                                              mojo::ScopedMessagePipeHandle)>;
   class TestApi {
    public:
     explicit TestApi(InterfaceProvider* provider) : provider_(provider) {}
     ~TestApi() {}
 
     void SetBinderForName(
         const std::string& name,
         const base::Callback<void(mojo::ScopedMessagePipeHandle)>& binder) {
       provider_->SetBinderForName(name, binder);
     }
 
     void ClearBinders() {
       provider_->ClearBinders();
     }
 
    private:
     InterfaceProvider* provider_;
     DISALLOW_COPY_AND_ASSIGN(TestApi);
   };
 
   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(); }
 
   // Sets a closure to be run when the remote InterfaceProvider pipe is closed.
   void SetConnectionLostClosure(const base::Closure& connection_lost_closure);
 
   base::WeakPtr<InterfaceProvider> GetWeakPtr();
 
   // Binds |ptr| to an implementation of Interface in the remote application.
   // |ptr| can immediately be used to start sending requests to the remote
@@ skipping 20 matching lines @@
   }
   void ClearBinders();
 
   using BinderMap = std::map<
       std::string, base::Callback<void(mojo::ScopedMessagePipeHandle)>>;
   BinderMap binders_;
 
   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);
 };
 
 }  // namespace shell
 
 #endif  // SERVICES_SHELL_PUBLIC_CPP_INTERFACE_PROVIDER_H_