Enable overriding interface binders for any services running in current process.

services/service_manager/public/cpp/interface_binder.h

Index: services/service_manager/public/cpp/interface_binder.h
diff --git a/services/service_manager/public/cpp/interface_binder.h b/services/service_manager/public/cpp/interface_binder.h
index 0f4845bab1168e76bd4f73f5c0c66636333606b8..6e1c2fc45a6ff951abdefb32d66048b512218ed7 100644
--- a/services/service_manager/public/cpp/interface_binder.h
+++ b/services/service_manager/public/cpp/interface_binder.h
@@ -89,6 +89,33 @@ class GenericCallbackBinder : public InterfaceBinder {
   DISALLOW_COPY_AND_ASSIGN(GenericCallbackBinder);
 };
 
+class FullCallbackBinder : public InterfaceBinder {

[Ken Rockot(use gerrit already), 2017/05/11 02:32:08]

Could you please just modify GenericCallbackBinder to instead use the full
callback signature? It can have a constructor which still takes a
base::Callback<void(mojo::ScopedMessagePipeHandle)>, and we can just adapt that
to the full signature by binding a private helper method.

[leonhsl(Using Gerrit), 2017/05/11 03:10:04]

Done. Thank you very much! I should have done such way.

+ public:
+  using BindCallback = base::Callback<void(const BindSourceInfo&,
+                                           const std::string&,
+                                           mojo::ScopedMessagePipeHandle)>;
+
+  FullCallbackBinder(
+      const BindCallback& callback,
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+  ~FullCallbackBinder() override;
+
+ private:
+  // InterfaceBinder:
+  void BindInterface(const BindSourceInfo& source_info,
+                     const std::string& interface_name,
+                     mojo::ScopedMessagePipeHandle handle) override;
+
+  static void RunCallback(const BindCallback& callback,
+                          const BindSourceInfo& source_info,
+                          const std::string& interface_name,
+                          mojo::ScopedMessagePipeHandle client_handle);
+
+  const BindCallback callback_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  DISALLOW_COPY_AND_ASSIGN(FullCallbackBinder);
+};
+
 }  // namespace service_manager
 
 #endif  // SERVICES_SERVICE_MANAGER_PUBLIC_CPP_INTERFACE_BINDER_H_