Bug 1591328 - Remove obsolete nsContentTitleSettingEvent. r=mossop

Differential Revision: https://phabricator.services.mozilla.com/D53775

--HG--
extra : moz-landing-system : lando

xpfe/appshell/nsContentTreeOwner.cpp

@@ -734,28 +734,6 @@ nsContentTreeOwner::ProvideWindow(
 // nsContentTreeOwner: Accessors
 //*****************************************************************************
 
-#if defined(XP_MACOSX)
-class nsContentTitleSettingEvent : public Runnable {
- public:
-  nsContentTitleSettingEvent(dom::Element* dse, const nsAString& wtm)
-      : Runnable("nsContentTitleSettingEvent"),
-        mElement(dse),
-        mTitleDefault(wtm) {}
-
-  NS_IMETHOD Run() override {
-    ErrorResult rv;
-    mElement->SetAttribute(NS_LITERAL_STRING("titledefault"), mTitleDefault,
-                           rv);
-    mElement->RemoveAttribute(NS_LITERAL_STRING("titlemodifier"), rv);
-    return NS_OK;
-  }
-
- private:
-  nsCOMPtr<dom::Element> mElement;
-  nsString mTitleDefault;
-};
-#endif
-
 void nsContentTreeOwner::AppWindow(mozilla::AppWindow* aAppWindow) {
   mAppWindow = aAppWindow;
 }