Finish eliminating PlatformWindowMus

ui/platform_window/stub/stub_window.cc

 // Copyright 2015 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 "ui/platform_window/stub/stub_window.h"
 
 #include "ui/platform_window/platform_window_delegate.h"
 
 namespace ui {
 
 StubWindow::StubWindow(PlatformWindowDelegate* delegate) : delegate_(delegate) {
-  delegate_->OnAcceleratedWidgetAvailable(gfx::kNullAcceleratedWidget, 1.f);
+  if (delegate_)
+    delegate_->OnAcceleratedWidgetAvailable(gfx::kNullAcceleratedWidget, 1.f);
 }
 
 StubWindow::~StubWindow() {
 }
 
 void StubWindow::Show() {
 }
 
 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() {
   return bounds_;
 }
 
 void StubWindow::SetTitle(const base::string16& title) {}
 
 void StubWindow::SetCapture() {
 }
@@ skipping 20 matching lines @@
 }
 
 void StubWindow::ConfineCursorToBounds(const gfx::Rect& bounds) {
 }
 
 PlatformImeController* StubWindow::GetPlatformImeController() {
   return nullptr;
 }
 
 }  // namespace ui