Add SetClient method implementation to InterfaceImpl.

mojo/public/cpp/bindings/interface_impl.h

 // Copyright 2014 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 MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_IMPL_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_IMPL_H_
 
 #include "mojo/public/cpp/bindings/lib/interface_impl_internal.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
 
 // InterfaceImpl<..> is designed to be the base class of an interface
 // implementation. It may be bound to a pipe or a proxy, see BindToPipe and
 // BindToProxy.
 //
 // NOTE: A base class of WithErrorHandler<Interface> is used to avoid multiple
 // inheritance. This base class inserts the signature of ErrorHandler into the
 // inheritance chain.
 template <typename Interface>
 class InterfaceImpl : public WithErrorHandler<Interface> {
  public:
+  typedef typename Interface::Client Client;
+
   InterfaceImpl() : internal_state_(this) {}
   virtual ~InterfaceImpl() {}
 
   // Subclasses must handle connection errors.
   virtual void OnConnectionError() = 0;
 
+  // We override SetClient here so subclasses don't each have to.
+  virtual void SetClient(Client* client) MOJO_OVERRIDE {
+    internal_state_.set_client(client);
+  }
+  Client* client() { return internal_state_.client(); }
+
   // DO NOT USE. Exposed only for internal use and for testing.
   internal::InterfaceImplState<Interface>* internal_state() {
     return &internal_state_;
   }
 
  private:
   internal::InterfaceImplState<Interface> internal_state_;
   MOJO_DISALLOW_COPY_AND_ASSIGN(InterfaceImpl);
 };
 
@@ skipping 31 matching lines @@
 Impl* BindToProxy(Impl* instance,
                   InterfacePtr<Interface>* ptr,
                   MojoAsyncWaiter* waiter = GetDefaultAsyncWaiter()) {
   instance->internal_state()->BindProxy(ptr, waiter);
   return instance;
 }
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_IMPL_H_