RendererCompositorFrameSink should handle local surface id allocation

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 093491511694b133333f9365eb3a9d905d365066..9914db5ce83b44decb9fab14cf8324256ae85c9c 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -1820,10 +1820,36 @@ bool RenderWidgetHostImpl::OnSwapCompositorFrame(
   ViewHostMsg_SwapCompositorFrame::Param param;
   if (!ViewHostMsg_SwapCompositorFrame::Read(&message, &param))
     return false;
-  cc::CompositorFrame frame(std::move(std::get<1>(param)));
   uint32_t compositor_frame_sink_id = std::get<0>(param);
+  cc::LocalSurfaceId local_surface_id = std::get<1>(param);
+  cc::CompositorFrame frame(std::move(std::get<2>(param)));
   std::vector<IPC::Message> messages_to_deliver_with_frame;
-  messages_to_deliver_with_frame.swap(std::get<2>(param));
+  messages_to_deliver_with_frame.swap(std::get<3>(param));
+
+  // The renderer should not send empty frames.
+  if (frame.render_pass_list.empty()) {
+    DLOG(ERROR) << "Renderer sent an empty frame.";
+    return false;
+  }
+
+  // The renderer must allocate a new LocalSurfaceId if frame size or device
+  // scale factor changes.
+  float device_scale_factor = frame.metadata.device_scale_factor;
+  const gfx::Size& frame_size =
+      frame.render_pass_list.back()->output_rect.size();
+  if (local_surface_id == last_local_surface_id_ &&
+      (frame_size != last_frame_size_ ||
+       device_scale_factor != last_device_scale_factor_)) {
+    DLOG(ERROR) << "Renderer submitted frame of wrong size to its surface."
+                << " Expected: size=" << last_frame_size_.ToString()
+                << ",scale=" << last_device_scale_factor_
+                << " Received: size=" << frame_size.ToString()
+                << ",scale=" << device_scale_factor;
+    return false;
+  }
+  last_local_surface_id_ = local_surface_id;
+  last_frame_size_ = frame_size;
+  last_device_scale_factor_ = device_scale_factor;
 
   if (frame.metadata.begin_frame_ack.sequence_number <
       cc::BeginFrameArgs::kStartingFrameNumber) {
@@ -1856,7 +1882,8 @@ bool RenderWidgetHostImpl::OnSwapCompositorFrame(
   // compositor frame can arrive before the navigation commit message that
   // updates that value.
   if (view_ && frame.metadata.content_source_id >= current_content_source_id_) {
-    view_->OnSwapCompositorFrame(compositor_frame_sink_id, std::move(frame));
+    view_->OnSwapCompositorFrame(compositor_frame_sink_id, local_surface_id,
+                                 std::move(frame));
     view_->DidReceiveRendererFrame();
   } else {
     cc::ReturnedResourceArray resources;