[Chromecast] Use PendingReceiver for external Mojo BindInterface

To match the semantics of the new PendingReceiver / Remote APIs.

Merge-With: eureka-internal/342617
Change-Id: I1cfed9313351dff96307b1e63bb2ed4d1e1053b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1959927Reviewed-by: Yuchen Liu <yucliu@chromium.org>
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#723471}

chromecast/external_mojo/external_service_support/external_connector.h

@@ -57,16 +57,8 @@ class ExternalConnector {
   // will remain in progress until the service is registered.
   template <typename Interface>
   void BindInterface(const std::string& service_name,
-                     mojo::InterfacePtr<Interface>* ptr) {
-    BindInterface(service_name, Interface::Name_,
-                  mojo::MakeRequest(ptr).PassMessagePipe());
-  }
-
-  template <typename Interface>
-  void BindInterface(const std::string& service_name,
-                     mojo::PendingRemote<Interface>* ptr) {
-    BindInterface(service_name, Interface::Name_,
-                  ptr->InitWithNewPipeAndPassReceiver().PassPipe());
+                     mojo::PendingReceiver<Interface> receiver) {
+    BindInterface(service_name, Interface::Name_, receiver.PassPipe());
   }
 
   virtual void BindInterface(const std::string& service_name,