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..da7fd6227b78c7e3430fa07dfcd07d093e99c047 100644
--- a/ui/platform_window/stub/stub_window.cc
+++ b/ui/platform_window/stub/stub_window.cc
@@ -9,7 +9,8 @@
 namespace ui {
 
 StubWindow::StubWindow(PlatformWindowDelegate* delegate) : delegate_(delegate) {
-  delegate_->OnAcceleratedWidgetAvailable(gfx::kNullAcceleratedWidget, 1.f);
+  if (delegate_)
+    delegate_->OnAcceleratedWidgetAvailable(gfx::kNullAcceleratedWidget, 1.f);
 }
 
 StubWindow::~StubWindow() {
@@ -22,14 +23,16 @@ 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() {