Add a blink InterfaceRegistry.

third_party/WebKit/public/platform/InterfaceRegistry.h

+// Copyright 2016 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 InterfaceRegistry_h
+#define InterfaceRegistry_h
+
+#include "mojo/public/cpp/system/message_pipe.h"
+#include "public/platform/WebCallbacks.h"
+#include "public/platform/WebCommon.h"
+
+#if INSIDE_BLINK
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "wtf/Functional.h"
+#endif
+
+namespace blink {
+
+using InterfaceFactory = WebCallbacks<mojo::ScopedMessagePipeHandle, void>;

[esprehn, 2016/10/13 22:31:55]

Can we use Function and Closure directly instead?

[Sam McNally, 2016/10/14 00:35:57]

Done.

+
+class BLINK_PLATFORM_EXPORT InterfaceRegistry {
+ public:
+  virtual void addInterface(const char* name,
+                            std::unique_ptr<InterfaceFactory>) = 0;
+
+#if INSIDE_BLINK
+  static InterfaceRegistry* getEmptyInterfaceRegistry();
+
+  template <typename Interface>
+  void addInterface(
+      std::unique_ptr<WTF::Function<void(mojo::InterfaceRequest<Interface>)>>
+          factory) {
+    addInterface(Interface::Name_,
+                 std::unique_ptr<InterfaceFactory>(
+                     new CallbackImpl<Interface>(std::move(factory))));

[esprehn, 2016/10/13 22:31:55]

convertToBaseCallback ?

[Sam McNally, 2016/10/14 00:35:57]

Done.

+  }
+
+ private:
+  template <typename Interface>
+  class CallbackImpl : public InterfaceFactory {
+   public:
+    CallbackImpl(
+        std::unique_ptr<WTF::Function<void(mojo::InterfaceRequest<Interface>)>>
+            factory)
+        : m_factory(std::move(factory)) {}
+
+    void onSuccess(mojo::ScopedMessagePipeHandle handle) override {
+      (*m_factory)(mojo::MakeRequest<Interface>(std::move(handle)));
+    }
+
+    void onError() {}

[esprehn, 2016/10/13 22:31:55]

Yeah you definitely want to use convertToBaseCallback and base::Callback instead
:)

[Sam McNally, 2016/10/14 00:35:57]

Done.

+
+   private:
+    std::unique_ptr<WTF::Function<void(mojo::InterfaceRequest<Interface>)>>
+        m_factory;
+  };
+#endif  // INSIDE_BLINK
+};
+
+}  // namespace blink
+
+#endif