diff --git content/browser/renderer_host/browser_compositor_view_mac.h content/browser/renderer_host/browser_compositor_view_mac.h
index 8d92b06..618d23e 100644
--- content/browser/renderer_host/browser_compositor_view_mac.h
+++ content/browser/renderer_host/browser_compositor_view_mac.h
@@ -56,9 +56,11 @@ class BrowserCompositorMac : public cc::BeginFrameObserver,
 
   // These will not return nullptr until Destroy is called.
   DelegatedFrameHost* GetDelegatedFrameHost();
+  ui::Layer* GetRootLayer() { return root_layer_.get(); }
 
   // This may return nullptr, if this has detached itself from its
   // ui::Compositor.
+  ui::Compositor* GetCompositor();
   ui::AcceleratedWidgetMac* GetAcceleratedWidgetMac();
 
   void SwapCompositorFrame(uint32_t output_surface_id,
diff --git content/browser/renderer_host/browser_compositor_view_mac.mm content/browser/renderer_host/browser_compositor_view_mac.mm
index 219effe..5122a99 100644
--- content/browser/renderer_host/browser_compositor_view_mac.mm
+++ content/browser/renderer_host/browser_compositor_view_mac.mm
@@ -198,6 +198,12 @@ BrowserCompositorMac::~BrowserCompositorMac() {
     g_spare_recyclable_compositors.Get().clear();
 }
 
+ui::Compositor* BrowserCompositorMac::GetCompositor() {
+  if (recyclable_compositor_)
+    return recyclable_compositor_->compositor();
+  return nullptr;
+}
+
 ui::AcceleratedWidgetMac* BrowserCompositorMac::GetAcceleratedWidgetMac() {
   if (recyclable_compositor_)
     return recyclable_compositor_->accelerated_widget_mac();
@@ -414,8 +420,13 @@ SkColor BrowserCompositorMac::DelegatedFrameHostGetGutterColor(
 }
 
 gfx::Size BrowserCompositorMac::DelegatedFrameHostDesiredSizeInDIP() const {
-  NSRect bounds = [client_->BrowserCompositorMacGetNSView() bounds];
-  return gfx::Size(bounds.size.width, bounds.size.height);
+  // View will be nil with CEF OSR.
+  NSView* view = client_->BrowserCompositorMacGetNSView();
+  if (view) {
+    NSRect bounds = [view bounds];
+    return gfx::Size(bounds.size.width, bounds.size.height);
+  }
+  return root_layer_->bounds().size();
 }
 
 bool BrowserCompositorMac::DelegatedFrameCanCreateResizeLock() const {