Fix icon on Windows XP taskbar

ui/views/win/hwnd_message_handler.cc

Index: ui/views/win/hwnd_message_handler.cc
diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index 01b3f7dcc052c504227acdfc4665d051b0b245fa..322a21efc2005e58eef1fff52ec06941218ba5f3 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -913,9 +913,16 @@ void HWNDMessageHandler::DispatchKeyEventPostIME(const ui::KeyEvent& key) {
 
 HICON HWNDMessageHandler::GetDefaultWindowIcon() const {
   if (use_system_default_icon_)
-    return NULL;
+    return nullptr;
   return ViewsDelegate::views_delegate ?
-      ViewsDelegate::views_delegate->GetDefaultWindowIcon() : NULL;
+      ViewsDelegate::views_delegate->GetDefaultWindowIcon() : nullptr;
+}
+
+HICON HWNDMessageHandler::GetSmallWindowIcon() const {
+  if (use_system_default_icon_)
+    return nullptr;
+  return ViewsDelegate::views_delegate ?
+      ViewsDelegate::views_delegate->GetSmallWindowIcon() : nullptr;
 }
 
 LRESULT HWNDMessageHandler::OnWndProc(UINT message,