[mojo] Enable ServiceRegistryImpl to override remote services

content/common/mojo/service_registry_impl.h

Index: content/common/mojo/service_registry_impl.h
diff --git a/content/common/mojo/service_registry_impl.h b/content/common/mojo/service_registry_impl.h
index 5e4fd73fd917b8c4874f5965df9ca52bb5f1e4a4..a51c67cfeed072ded9f685a3a1cca461666ecd67 100644
--- a/content/common/mojo/service_registry_impl.h
+++ b/content/common/mojo/service_registry_impl.h
@@ -24,6 +24,8 @@ class CONTENT_EXPORT ServiceRegistryImpl
     : public ServiceRegistry,
       public NON_EXPORTED_BASE(mojo::ServiceProvider) {
  public:
+  using ServiceFactory = base::Callback<void(mojo::ScopedMessagePipeHandle)>;
+
   ServiceRegistryImpl();
   ~ServiceRegistryImpl() override;
 
@@ -36,10 +38,15 @@ class CONTENT_EXPORT ServiceRegistryImpl
   // ServiceProvider.
   void BindRemoteServiceProvider(mojo::ServiceProviderPtr service_provider);
 
+  // Registers a local service factory to intercept ConnectToRemoteService
+  // requests instead of actually connecting to the remote registry. Used only
+  // for testing.
+  void AddServiceOverrideForTesting(const std::string& service_name,
+                                    const ServiceFactory& service_factory);
+
   // ServiceRegistry overrides.
   void AddService(const std::string& service_name,
-                  const base::Callback<void(mojo::ScopedMessagePipeHandle)>
-                      service_factory) override;
+                  const ServiceFactory service_factory) override;
   void RemoveService(const std::string& service_name) override;
   void ConnectToRemoteService(const base::StringPiece& service_name,
                               mojo::ScopedMessagePipeHandle handle) override;
@@ -58,11 +65,12 @@ class CONTENT_EXPORT ServiceRegistryImpl
   mojo::Binding<mojo::ServiceProvider> binding_;
   mojo::ServiceProviderPtr remote_provider_;
 
-  std::map<std::string, base::Callback<void(mojo::ScopedMessagePipeHandle)> >
-      service_factories_;
+  std::map<std::string, ServiceFactory> service_factories_;
   std::queue<std::pair<std::string, mojo::MessagePipeHandle> >
       pending_connects_;
 
+  std::map<std::string, ServiceFactory> service_overrides_;
+
   base::WeakPtrFactory<ServiceRegistry> weak_factory_;
 };