Make stream captures work on canvases that are not in the DOM.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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/renderer/gpu/render_widget_compositor.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <limits>
@@ skipping 1093 matching lines @@
 void RenderWidgetCompositor::DidCompletePageScaleAnimation() {
   delegate_->DidCompletePageScaleAnimation();
 }
 
 void RenderWidgetCompositor::RequestScheduleAnimation() {
   delegate_->RequestScheduleAnimation();
 }
 
 void RenderWidgetCompositor::DidSubmitCompositorFrame() {}
 
-void RenderWidgetCompositor::DidLoseCompositorFrameSink() {
-  // The CompositorFrameSink is not lost in layout tests (single thread mode).
-  NOTREACHED();
-}
+void RenderWidgetCompositor::DidLoseCompositorFrameSink() {}
 
 void RenderWidgetCompositor::SetFrameSinkId(
     const cc::FrameSinkId& frame_sink_id) {
   frame_sink_id_ = frame_sink_id;
   layer_tree_host_->SetFrameSinkId(frame_sink_id);
 }
 
 void RenderWidgetCompositor::SetPaintedDeviceScaleFactor(
     float device_scale) {
   layer_tree_host_->SetPaintedDeviceScaleFactor(device_scale);
 }
 
 void RenderWidgetCompositor::SetDeviceColorSpace(
     const gfx::ColorSpace& color_space) {
   layer_tree_host_->SetDeviceColorSpace(color_space);
 }
 
 void RenderWidgetCompositor::SetIsForOopif(bool is_for_oopif) {
   is_for_oopif_ = is_for_oopif;
 }
 
 }  // namespace content