WIP: move OffscreenCanvas into new display compositor

components/display_compositor/gpu_compositor_frame_sink_base.cc

Index: components/display_compositor/gpu_compositor_frame_sink_base.cc
diff --git a/components/display_compositor/gpu_compositor_frame_sink_base.cc b/components/display_compositor/gpu_compositor_frame_sink_base.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ea04fc53c00604a78b34090148f92b6aec718233
--- /dev/null
+++ b/components/display_compositor/gpu_compositor_frame_sink_base.cc
@@ -0,0 +1,46 @@
+// 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 "components/display_compositor/gpu_compositor_frame_sink_base.h"
+
+#include "cc/surfaces/surface_reference.h"
+
+namespace display_compositor {
+
+GpuCompositorFrameSinkBase::GpuCompositorFrameSinkBase(
+    GpuCompositorFrameSinkDelegate* delegate,
+    std::unique_ptr<cc::CompositorFrameSinkSupport> support,
+    cc::mojom::MojoCompositorFrameSinkPrivateRequest
+        compositor_frame_sink_private_request,
+    cc::mojom::MojoCompositorFrameSinkClientPtr client)
+    : GpuCompositorFrameSink(delegate, std::move(support), std::move(client)),
+      compositor_frame_sink_private_binding_(
+          this,
+          std::move(compositor_frame_sink_private_request)) {
+  compositor_frame_sink_private_binding_.set_connection_error_handler(
+      base::Bind(&GpuCompositorFrameSinkBase::OnPrivateConnectionLost,
+                 base::Unretained(this)));
+  SetPrivateConnectionLost(false);
+}
+
+GpuCompositorFrameSinkBase::~GpuCompositorFrameSinkBase() {}
+
+void GpuCompositorFrameSinkBase::AddChildFrameSink(
+    const cc::FrameSinkId& child_frame_sink_id) {
+  support_->AddChildFrameSink(child_frame_sink_id);
+}
+
+void GpuCompositorFrameSinkBase::RemoveChildFrameSink(
+    const cc::FrameSinkId& child_frame_sink_id) {
+  support_->RemoveChildFrameSink(child_frame_sink_id);
+}
+
+void GpuCompositorFrameSinkBase::OnPrivateConnectionLost() {
+  SetPrivateConnectionLost(true);
+  // Request destruction of |this| only if both connections are lost.
+  delegate_->OnPrivateConnectionLost(support_->frame_sink_id(),
+                                     GetClientConnectionLost());
+}
+
+}  // namespace display_compositor