Finish eliminating PlatformWindowMus

ui/platform_window/stub/stub_window.cc

Index: ui/platform_window/stub/stub_window.cc
diff --git a/ui/platform_window/stub/stub_window.cc b/ui/platform_window/stub/stub_window.cc
index a46f89d656dfe7a41f49fe855782c92ee0ea5b8f..bb635531fb75b3d35bfbe060fa93439c553a9b43 100644
--- a/ui/platform_window/stub/stub_window.cc
+++ b/ui/platform_window/stub/stub_window.cc
@@ -4,12 +4,16 @@
 
 #include "ui/platform_window/stub/stub_window.h"
 
+#include "ui/gfx/native_widget_types.h"
 #include "ui/platform_window/platform_window_delegate.h"
 
 namespace ui {
 
-StubWindow::StubWindow(PlatformWindowDelegate* delegate) : delegate_(delegate) {
-  delegate_->OnAcceleratedWidgetAvailable(gfx::kNullAcceleratedWidget, 1.f);
+StubWindow::StubWindow(
+    PlatformWindowDelegate* delegate, gfx::AcceleratedWidget accelerated_widget)
+    : delegate_(delegate) {
+  if (delegate_)
+    delegate_->OnAcceleratedWidgetAvailable(accelerated_widget, 1.f);
 }
 
 StubWindow::~StubWindow() {
@@ -22,14 +26,16 @@ void StubWindow::Hide() {
 }
 
 void StubWindow::Close() {
-  delegate_->OnClosed();
+  if (delegate_)
+    delegate_->OnClosed();
 }
 
 void StubWindow::SetBounds(const gfx::Rect& bounds) {
   if (bounds_ == bounds)
     return;
   bounds_ = bounds;
-  delegate_->OnBoundsChanged(bounds);
+  if (delegate_)
+    delegate_->OnBoundsChanged(bounds);
 }
 
 gfx::Rect StubWindow::GetBounds() {