Mojo: Use InterfaceFactory<Interface> for service registration

mojo/public/cpp/application/interface_provider.h

Index: mojo/public/cpp/application/interface_provider.h
diff --git a/mojo/public/cpp/application/interface_provider.h b/mojo/public/cpp/application/interface_provider.h
new file mode 100644
index 0000000000000000000000000000000000000000..0f4777cb21dbb5aa3da09712eb2ab10e868a3212
--- /dev/null
+++ b/mojo/public/cpp/application/interface_provider.h
@@ -0,0 +1,31 @@
+// 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_APPLICATION_INTERFACE_FACTORY_H_
+#define MOJO_PUBLIC_APPLICATION_INTERFACE_FACTORY_H_
+
+#include "mojo/public/cpp/bindings/interface_impl.h"
+#include "mojo/public/cpp/system/macros.h"
+
+namespace mojo {
+
+class ApplicationConnection;
+template <typename Interface>
+class InterfaceRequest;
+
+// Implement this class to provide implementations of a given interface and
+// bind them to incoming requests. The implementation of this class is
+// responsible for managing the lifetime of the implementations of the
+// interface.
+template <typename Interface>
+class InterfaceProvider {
+ public:
+  virtual ~InterfaceProvider() {}
+  virtual void BindToRequest(ApplicationConnection* connection,

[darin (slow to review), 2014/07/14 21:34:06]

I'm still a fan of using terminology like "create instance" here. The
InterfaceProvider is being asked to create an instance of a particular
interface.

BindToRequest seems wrong as the function doesn't take the thing that should be
bound. The subject of the call is unspecified. You could say
CreateInstanceAndBindToRequest. (What about if they want to use
WeakBindToRequest instead?)

I might even consider going further and renaming InterfaceProvider to
InterfaceFactory. It really is a factory of sorts.

I'm not so bothered by "Create*" normally implying a method that returns a heap
allocated object. If you think about a .mojom file, you might use "Create*" to
name functions that look very much like what I'm proposing.

  interface Foo {
    CreateBar(Bar& bar);
  };

[DaveMoore, 2014/07/15 00:08:29]

I see the Interface as an abstract definition and Service as a concrete
implementation of an Interface. So this thing isn't really providing an
Interface. It's providing an implementation.

On 2014/07/14 21:34:06, darin wrote:

+                             InterfaceRequest<Interface> request) = 0;
+};
+
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_APPLICATION_INTERFACE_FACTORY_H_