Mojo C++ bindings: support disconnect with a reason.

mojo/public/cpp/bindings/strong_binding.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_STRONG_BINDING_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_STRONG_BINDING_H_
 
 #include <memory>
+#include <string>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/public/cpp/bindings/connection_error_callback.h"
 #include "mojo/public/cpp/bindings/filter_chain.h"
 #include "mojo/public/cpp/bindings/interface_ptr.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 #include "mojo/public/cpp/bindings/lib/router.h"
 #include "mojo/public/cpp/bindings/message_header_validator.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace mojo {
 
 template <typename Interface>
@@ skipping 25 matching lines @@
     return binding->weak_factory_.GetWeakPtr();
   }
 
   // Note: The error handler must not delete the interface implementation.
   //
   // This method may only be called after this StrongBinding has been bound to a
   // message pipe.
   void set_connection_error_handler(const base::Closure& error_handler) {
     DCHECK(binding_.is_bound());
     connection_error_handler_ = error_handler;
+    connection_error_with_reason_handler_.Reset();
+  }
+
+  void set_connection_error_with_reason_handler(
+      const ConnectionErrorWithReasonCallback& error_handler) {
+    DCHECK(binding_.is_bound());
+    connection_error_with_reason_handler_ = error_handler;
+    connection_error_handler_.Reset();
   }
 
   // Forces the binding to close. This destroys the StrongBinding instance.
   void Close() { delete this; }
 
   Interface* impl() { return impl_.get(); }
 
   // Exposed for testing, should not generally be used.
   internal::Router* internal_router() { return binding_.internal_router(); }
 
   // Sends a message on the underlying message pipe and runs the current
   // message loop until its response is received. This can be used in tests to
   // verify that no message was sent on a message pipe in response to some
   // stimulus.
   void FlushForTesting() { binding_.FlushForTesting(); }
 
  private:
   StrongBinding(std::unique_ptr<Interface> impl,
                 InterfaceRequest<Interface> request)
       : impl_(std::move(impl)),
         binding_(impl_.get(), std::move(request)),
         weak_factory_(this) {
-    binding_.set_connection_error_handler(
+    binding_.set_connection_error_with_reason_handler(
         base::Bind(&StrongBinding::OnConnectionError, base::Unretained(this)));
   }
 
   ~StrongBinding() {}
 
-  void OnConnectionError() {
+  void OnConnectionError(uint32_t custom_reason,
+                         const std::string& description) {
     if (!connection_error_handler_.is_null())
       connection_error_handler_.Run();
+    else if (!connection_error_with_reason_handler_.is_null())
+      connection_error_with_reason_handler_.Run(custom_reason, description);
     Close();
   }
 
   std::unique_ptr<Interface> impl_;
   base::Closure connection_error_handler_;
+  ConnectionErrorWithReasonCallback connection_error_with_reason_handler_;
   Binding<Interface> binding_;
   base::WeakPtrFactory<StrongBinding> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(StrongBinding);
 };
 
 template <typename Interface, typename Impl>
 StrongBindingPtr<Interface> MakeStrongBinding(
     std::unique_ptr<Impl> impl,
     InterfaceRequest<Interface> request) {
   return StrongBinding<Interface>::Create(std::move(impl), std::move(request));
 }
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_STRONG_BINDING_H_