Mojo C++ bindings: don't DCEHCK in Binding::Close() when the binding is not bound.

mojo/public/cpp/bindings/lib/binding_state.h

 // 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDING_STATE_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDING_STATE_H_
 
 #include <memory>
 #include <utility>
 
@@ skipping 26 matching lines @@
 // methods to pass associated interface pointers or requests, there won't be
 // multiple interfaces running on the underlying message pipe. In that case, we
 // can use this specialization to reduce cost.
 template <typename Interface>
 class BindingState<Interface, false> {
  public:
   explicit BindingState(Interface* impl) : impl_(impl) {
     stub_.set_sink(impl_);
   }
 
-  ~BindingState() {
-    if (router_)
-      Close();
-  }
+  ~BindingState() { Close(); }
 
   void Bind(ScopedMessagePipeHandle handle,
             scoped_refptr<base::SingleThreadTaskRunner> runner) {
     DCHECK(!router_);
     internal::FilterChain filters;
     filters.Append<internal::MessageHeaderValidator>();
     filters.Append<typename Interface::RequestValidator_>();
 
     router_ =
         new internal::Router(std::move(handle), std::move(filters),
@@ skipping 14 matching lines @@
     router_->ResumeIncomingMethodCallProcessing();
   }
 
   bool WaitForIncomingMethodCall(
       MojoDeadline deadline = MOJO_DEADLINE_INDEFINITE) {
     DCHECK(router_);
     return router_->WaitForIncomingMessage(deadline);
   }
 
   void Close() {
-    DCHECK(router_);
+    if (!router_)
+      return;
+
     router_->CloseMessagePipe();
     DestroyRouter();
   }
 
   InterfaceRequest<Interface> Unbind() {
     InterfaceRequest<Interface> request =
         MakeRequest<Interface>(router_->PassMessagePipe());
     DestroyRouter();
     return std::move(request);
   }
@@ skipping 37 matching lines @@
 
 // Uses a multiplexing router. If |Interface| has methods to pass associated
 // interface pointers or requests, this specialization should be used.
 template <typename Interface>
 class BindingState<Interface, true> {
  public:
   explicit BindingState(Interface* impl) : impl_(impl) {
     stub_.set_sink(impl_);
   }
 
-  ~BindingState() {
-    if (router_)
-      Close();
-  }
+  ~BindingState() { Close(); }
 
   void Bind(ScopedMessagePipeHandle handle,
             scoped_refptr<base::SingleThreadTaskRunner> runner) {
     DCHECK(!router_);
 
     router_ = new internal::MultiplexRouter(false, std::move(handle), runner);
     stub_.serialization_context()->router = router_;
 
     endpoint_client_.reset(new internal::InterfaceEndpointClient(
         router_->CreateLocalEndpointHandle(internal::kMasterInterfaceId),
@@ skipping 17 matching lines @@
     router_->ResumeIncomingMethodCallProcessing();
   }
 
   bool WaitForIncomingMethodCall(
       MojoDeadline deadline = MOJO_DEADLINE_INDEFINITE) {
     DCHECK(router_);
     return router_->WaitForIncomingMessage(deadline);
   }
 
   void Close() {
-    DCHECK(router_);
+    if (!router_)
+      return;
+
     endpoint_client_.reset();
     router_->CloseMessagePipe();
     router_ = nullptr;
     connection_error_handler_.reset();
   }
 
   InterfaceRequest<Interface> Unbind() {
     endpoint_client_.reset();
     InterfaceRequest<Interface> request =
         MakeRequest<Interface>(router_->PassMessagePipe());
@@ skipping 33 matching lines @@
   Interface* impl_;
   Closure connection_error_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(BindingState);
 };
 
 }  // namesapce internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDING_STATE_H_