Make GPU back-pressure work with remote CALayers

content/browser/compositor/browser_compositor_view_private_mac.mm

Index: content/browser/compositor/browser_compositor_view_private_mac.mm
diff --git a/content/browser/compositor/browser_compositor_view_private_mac.mm b/content/browser/compositor/browser_compositor_view_private_mac.mm
index 8a1b392484dce56907f13a28a1910d08fd42cae8..90c834054313df4d868f3e913cf59c09f8a70d05 100644
--- a/content/browser/compositor/browser_compositor_view_private_mac.mm
+++ b/content/browser/compositor/browser_compositor_view_private_mac.mm
@@ -91,15 +91,11 @@ void BrowserCompositorViewMacInternal::ResetClient() {
   ScopedCAActionDisabler disabler;
 
   [flipped_layer_ removeFromSuperlayer];
+  DestroyIOSurfaceLayer(io_surface_layer_);
+  DestroyCAContextLayer(ca_context_layer_);
+  DestroySoftwareLayer();
 
-  [io_surface_layer_ removeFromSuperlayer];
-  [io_surface_layer_ resetClient];
-  io_surface_layer_.reset();
   accelerated_output_surface_id_ = 0;
-
-  [software_layer_ removeFromSuperlayer];
-  software_layer_.reset();
-
   last_swap_size_dip_ = gfx::Size();
 
   compositor_->SetScaleAndSize(1.0, gfx::Size(0, 0));
@@ -112,6 +108,12 @@ bool BrowserCompositorViewMacInternal::HasFrameOfSize(
   return last_swap_size_dip_ == dip_size;
 }
 
+int BrowserCompositorViewMacInternal::GetRendererID() const {
+  if (io_surface_layer_)
+    return [io_surface_layer_ iosurface]->GetRendererID();
+  return 0;
+}
+
 void BrowserCompositorViewMacInternal::BeginPumpingFrames() {
   [io_surface_layer_ beginPumpingFrames];
 }