Introduce ContextObserver

third_party/WebKit/Source/core/frame/BarProp.h

Index: third_party/WebKit/Source/core/frame/BarProp.h
diff --git a/third_party/WebKit/Source/core/frame/BarProp.h b/third_party/WebKit/Source/core/frame/BarProp.h
index 6de982b4505e2254b4dc6fa346d7542364b68500..26c93dde780f0125d8c1e61818923f7f3a1bc807 100644
--- a/third_party/WebKit/Source/core/frame/BarProp.h
+++ b/third_party/WebKit/Source/core/frame/BarProp.h
@@ -30,7 +30,7 @@
 #define BarProp_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
-#include "core/frame/DOMWindowProperty.h"
+#include "core/dom/ContextLifecycleObserver.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
@@ -39,7 +39,7 @@ class LocalFrame;
 
 class BarProp final : public GarbageCollected<BarProp>,
                       public ScriptWrappable,
-                      public DOMWindowProperty {
+                      public ContextObserver {
   DEFINE_WRAPPERTYPEINFO();
   USING_GARBAGE_COLLECTED_MIXIN(BarProp);