[remoteobjects] Implement listing object methods in the renderer

This CL adds an implementation of EnumerateNamedProperties() that ends up
calling a remote GetMethods() method on a RemoteObject mojo remote.
The remote will be connected to a RemoteObject implementation
in follow-up CLs.

Bug: 794320
Change-Id: Ia3748d6842608e56b5c7985147f28985feabde93
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1962985Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Commit-Queue: Oksana Zhuravlova <oksamyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727591}

third_party/blink/renderer/modules/remote_objects/remote_object.cc

@@ -31,8 +31,16 @@ v8::Local<v8::Value> RemoteObject::GetNamedProperty(
 
 std::vector<std::string> RemoteObject::EnumerateNamedProperties(
     v8::Isolate* isolate) {
-  // TODO(crbug.com/794320): implement this.
-  return std::vector<std::string>();
+  if (!object_.is_bound()) {
+    gateway_->BindRemoteObjectReceiver(object_id_,
+                                       object_.BindNewPipeAndPassReceiver());
+  }
+  WTF::Vector<WTF::String> methods;
+  object_->GetMethods(&methods);
+  std::vector<std::string> result;
+  for (const auto& method : methods)
+    result.push_back(method.Utf8());
+  return result;
 }
 
 }  // namespace blink

third_party/blink/renderer/modules/remote_objects/remote_object.h

@@ -39,6 +39,7 @@ class RemoteObject : public gin::Wrappable<RemoteObject>,
 
  private:
   WeakPersistent<RemoteObjectGatewayImpl> gateway_{nullptr};
+  mojo::Remote<mojom::blink::RemoteObject> object_;
   int32_t object_id_;
 };
 

third_party/blink/renderer/modules/remote_objects/remote_object_gateway_impl.cc

@@ -9,6 +9,8 @@
 #include "third_party/blink/renderer/platform/bindings/v8_binding.h"
 #include "third_party/blink/renderer/platform/bindings/v8_per_isolate_data.h"
 
+#undef GetObject
+
 namespace blink {
 
 // static
@@ -94,6 +96,12 @@ void RemoteObjectGatewayImpl::RemoveNamedObject(const WTF::String& name) {
   named_objects_.erase(iter);
 }
 
+void RemoteObjectGatewayImpl::BindRemoteObjectReceiver(
+    int32_t object_id,
+    mojo::PendingReceiver<mojom::blink::RemoteObject> receiver) {
+  object_host_->GetObject(object_id, std::move(receiver));
+}
+
 // static
 void RemoteObjectGatewayFactoryImpl::Create(
     LocalFrame* frame,

third_party/blink/renderer/modules/remote_objects/remote_object_gateway_impl.h

@@ -54,6 +54,10 @@ class MODULES_EXPORT RemoteObjectGatewayImpl
     Supplement<LocalFrame>::Trace(visitor);
   }
 
+  void BindRemoteObjectReceiver(
+      int32_t object_id,
+      mojo::PendingReceiver<mojom::blink::RemoteObject>);
+
  private:
   // mojom::blink::RemoteObjectGateway
   void AddNamedObject(const WTF::String& name, int32_t id) override;