Convert offscreen canvas to use FrameSinkManagerHost.

content/browser/compositor/gpu_process_transport_factory.cc

Index: content/browser/compositor/gpu_process_transport_factory.cc
diff --git a/content/browser/compositor/gpu_process_transport_factory.cc b/content/browser/compositor/gpu_process_transport_factory.cc
index 54b71195e9a8b7ffdcadc17a393d38cc781ea407..ac22112c31cf8d69db46b8edd7707800bf83e7f0 100644
--- a/content/browser/compositor/gpu_process_transport_factory.cc
+++ b/content/browser/compositor/gpu_process_transport_factory.cc
@@ -51,6 +51,7 @@
 #include "gpu/vulkan/features.h"
 #include "services/service_manager/runner/common/client_util.h"
 #include "services/ui/public/cpp/gpu/context_provider_command_buffer.h"
+#include "services/ui/surfaces/display_compositor.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_constants.h"
@@ -195,7 +196,8 @@ GpuProcessTransportFactory::GpuProcessTransportFactory()
       callback_factory_(this) {
   cc::SetClientNameForMetrics("Browser");
 
-  surface_manager_ = base::WrapUnique(new cc::SurfaceManager);
+  display_compositor_ = base::MakeUnique<ui::DisplayCompositor>(
+      nullptr, MakeRequest(&display_compositor_ptr_), nullptr);
 
   task_graph_runner_->Start("CompositorTileWorker1",
                             base::SimpleThread::Options());
@@ -597,12 +599,12 @@ void GpuProcessTransportFactory::EstablishedGpuChannel(
   auto compositor_frame_sink =
       vulkan_context_provider
           ? base::MakeUnique<cc::DirectCompositorFrameSink>(
-                compositor->frame_sink_id(), surface_manager_.get(),
+                compositor->frame_sink_id(), GetSurfaceManager(),
                 data->display.get(),
                 static_cast<scoped_refptr<cc::VulkanContextProvider>>(
                     vulkan_context_provider))
           : base::MakeUnique<cc::DirectCompositorFrameSink>(
-                compositor->frame_sink_id(), surface_manager_.get(),
+                compositor->frame_sink_id(), GetSurfaceManager(),
                 data->display.get(), context_provider,
                 shared_worker_context_provider_, GetGpuMemoryBufferManager(),
                 HostSharedBitmapManager::current());
@@ -792,7 +794,12 @@ void GpuProcessTransportFactory::RemoveObserver(
 }
 
 cc::SurfaceManager* GpuProcessTransportFactory::GetSurfaceManager() {
-  return surface_manager_.get();
+  return display_compositor_->surface_manager();
+}
+
+cc::mojom::DisplayCompositor*
+GpuProcessTransportFactory::GetDisplayCompositor() {
+  return display_compositor_ptr_.get();
 }
 
 display_compositor::GLHelper* GpuProcessTransportFactory::GetGLHelper() {