Mojo C++ Bindings: Introduce mojo::SupportsStrongBinding

mojo/public/cpp/bindings/tests/associated_interface_unittest.cc

 // Copyright 2015 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.
 
 #include <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 45 matching lines @@
 
   void set_connection_error_handler(const base::Closure& handler) {
     binding_.set_connection_error_handler(handler);
   }
 
  private:
   AssociatedBinding<IntegerSender> binding_;
   base::Callback<void(int32_t)> notify_send_method_called_;
 };
 
-class IntegerSenderConnectionImpl : public IntegerSenderConnection {
+class IntegerSenderConnectionImpl
+    : public SupportsStrongBinding<IntegerSenderConnection> {
  public:
   explicit IntegerSenderConnectionImpl(
       InterfaceRequest<IntegerSenderConnection> request)
       : binding_(this, std::move(request)) {}
 
   ~IntegerSenderConnectionImpl() override {}
 
   void GetSender(AssociatedInterfaceRequest<IntegerSender> sender) override {
     IntegerSenderImpl* sender_impl = new IntegerSenderImpl(std::move(sender));
     sender_impl->set_connection_error_handler(
@@ skipping 969 matching lines @@
       thread_safe_sender);
   other_thread.message_loop()->task_runner()->PostTask(FROM_HERE, run_method);
 
   // Block until the method callback is called on the background thread.
   run_loop.Run();
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo