Remove more oilpan.

sky/engine/core/page/Page.h

Index: sky/engine/core/page/Page.h
diff --git a/sky/engine/core/page/Page.h b/sky/engine/core/page/Page.h
index a725665301f03263c9aa24b1300da53994257dee..ab3028416ff052a06d2da69e88ba9d3d82e5b45d 100644
--- a/sky/engine/core/page/Page.h
+++ b/sky/engine/core/page/Page.h
@@ -65,8 +65,7 @@ typedef uint64_t LinkHash;
 
 float deviceScaleFactor(LocalFrame*);
 
-class Page final : public DummyBase<Page>, public Supplementable<Page>, public LifecycleContext<Page>, public SettingsDelegate {
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Page);
+class Page final : public Supplementable<Page>, public LifecycleContext<Page>, public SettingsDelegate {
     WTF_MAKE_NONCOPYABLE(Page);
     friend class Settings;
 public:
@@ -145,7 +144,7 @@ public:
 
     double timerAlignmentInterval() const;
 
-    class MultisamplingChangedObserver : public DummyBase<void> {
+    class MultisamplingChangedObserver {
     public:
         virtual void multisamplingChanged(bool) = 0;
     };