Use MojoCompositorFrameSink in RendererCompositorFrameSink

content/browser/frame_sink_provider_impl.cc

+// Copyright 2017 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.
+#include "content/browser/frame_sink_provider_impl.h"
+#include "content/browser/renderer_host/render_widget_host_impl.h"
+
+namespace content {
+
+FrameSinkProviderImpl::FrameSinkProviderImpl(int32_t process_id)
+    : process_id_(process_id), binding_(this) {}
+
+FrameSinkProviderImpl::~FrameSinkProviderImpl() = default;
+
+void FrameSinkProviderImpl::Bind(mojom::FrameSinkProviderRequest request) {
+  if (binding_.is_bound()) {

[Fady Samuel, 2017/04/10 02:28:37]

Should this be a DCHECK instead or can a malicious renderer cause this to get
called twice?

[Saman Sami, 2017/04/10 02:37:47]

Since the request comes from the renderer, I think we shouldn't DCHECK. rockot
can provide a better answer.

+    LOG(ERROR) << "Received multiple requests for FrameSinkProvider. "
+               << "There should be only one instance per renderer.";
+    return;
+  }
+  binding_.Bind(std::move(request));
+}
+
+void FrameSinkProviderImpl::CreateForWidget(
+    int32_t widget_id,

[Fady Samuel, 2017/04/10 02:28:37]

routing ID right?

[Saman Sami, 2017/04/10 02:37:47]

Those two are basically synonymous (I'm pretty sure I saw it used in other
places, I don't think I created this term?) and I would rather not use the term
that has Chrome IPC roots.

+    cc::mojom::MojoCompositorFrameSinkRequest request,
+    cc::mojom::MojoCompositorFrameSinkClientPtr client) {
+  RenderWidgetHostImpl* render_widget_host_impl =
+      RenderWidgetHostImpl::FromID(process_id_, widget_id);
+  if (!render_widget_host_impl) {
+    LOG(ERROR) << "No RenderWidgetHost exists with id " << widget_id;
+    return;
+  }
+  render_widget_host_impl->RequestMojoCompositorFrameSink(std::move(request),
+                                                          std::move(client));
+}
+
+}  // namespace content