Adds routed interface support between RenderFrameHost and RenderFrame

content/public/renderer/render_frame.h

Index: content/public/renderer/render_frame.h
diff --git a/content/public/renderer/render_frame.h b/content/public/renderer/render_frame.h
index 0ac29c8eecdab5aaa8ebc77b1f0e2422197520f6..da0b809abe8b5f2407fecc494a1e7c2d9c5010a1 100644
--- a/content/public/renderer/render_frame.h
+++ b/content/public/renderer/render_frame.h
@@ -13,8 +13,12 @@
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
 #include "content/public/common/console_message_level.h"
+#include "content/public/renderer/render_thread.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
+#include "ipc/ipc_sync_channel.h"
+#include "mojo/public/cpp/bindings/associated_interface_ptr.h"
+#include "mojo/public/cpp/bindings/associated_interface_request.h"
 #include "third_party/WebKit/public/platform/WebPageVisibilityState.h"
 #include "third_party/WebKit/public/web/WebNavigationPolicy.h"
 
@@ -155,6 +159,23 @@ class CONTENT_EXPORT RenderFrame : public IPC::Listener,
   // interfaces exposed to it by the application running in this frame.
   virtual shell::InterfaceProvider* GetRemoteInterfaces() = 0;
 
+  using GenericRoutedInterfaceFactory =
+      base::Callback<void(mojo::ScopedInterfaceEndpointHandle)>;
+
+  // Adds an associated interface factory to this frame, allowing the remote
+  // RenderFrameHost to acquire a proxy to the interface on this specific frame.
+  virtual void AddRoutedInterface(

[tibell, 2016/09/05 00:32:13]

It's a bit unfortunate that we couldn't instead have

    virtual shell::InterfaceRegistry* GetRoutedInterfaceRegistry() = 0;

and thus keep the interface more uniform (i.e. not have RenderFrame act like an
InterfaceRegistry itself. I guess that would require making InterfaceRegistry
entirely virtual.

Just a thought.

+      const base::StringPiece& name,
+      const GenericRoutedInterfaceFactory& factory) = 0;
+
+  virtual void RemoveRoutedInterface(const base::StringPiece& name) = 0;
+
+  // Binds an interface proxy to be associated with the remote RenderFrameHost
+  // in the browser process.
+  virtual void GetRemoteRoutedInterface(
+      const base::StringPiece& name,
+      mojo::ScopedInterfaceEndpointHandle handle) = 0;
+
 #if defined(ENABLE_PLUGINS)
   // Registers a plugin that has been marked peripheral. If the origin
   // whitelist is later updated and includes |content_origin|, then
@@ -229,13 +250,50 @@ class CONTENT_EXPORT RenderFrame : public IPC::Listener,
   // Returns the current visibility of the frame.
   virtual blink::WebPageVisibilityState GetVisibilityState() const = 0;
 
+  template <typename Interface>
+  void GetRemoteRoutedInterface(
+      mojo::AssociatedInterfacePtr<Interface>* proxy) {
+    IPC::ChannelProxy* channel = RenderThread::Get()->GetChannel();
+
+    // Tests may not have a channel set up. Since they clearly don't expect IPC
+    // to work, we can bind these interface requests to dead-ends.
+    if (!channel) {
+      mojo::GetDummyProxy(proxy);
+      return;
+    }
+
+    mojo::AssociatedInterfaceRequest<Interface> request = mojo::GetProxy(
+        proxy, channel->GetAssociatedGroup());
+    GetRemoteRoutedInterface(Interface::Name_, request.PassHandle());
+  }
+
+  template <typename Interface>
+  using RoutedInterfaceFactory =
+      base::Callback<void(mojo::AssociatedInterfaceRequest<Interface>)>;
+
+  template <typename Interface>
+  void AddRoutedInterface(const RoutedInterfaceFactory<Interface>& factory) {
+    AddRoutedInterface(Interface::Name_,
+                       base::Bind(&BindRoutedInterface<Interface>, factory));
+  }
+
  protected:
   ~RenderFrame() override {}
 
  private:
   // This interface should only be implemented inside content.
   friend class RenderFrameImpl;
+
   RenderFrame() {}
+
+  template <typename Interface>
+  static void BindRoutedInterface(
+      const RoutedInterfaceFactory<Interface>& factory,
+      mojo::ScopedInterfaceEndpointHandle handle) {
+    mojo::AssociatedInterfaceRequest<Interface> request;
+    request.Bind(std::move(handle));
+    factory.Run(std::move(request));
+  }
 };
 
 }  // namespace content