Revert "binding: Window-returning attributes return null if a Window is detached."

third_party/WebKit/Source/core/frame/DOMWindow.cpp

Index: third_party/WebKit/Source/core/frame/DOMWindow.cpp
diff --git a/third_party/WebKit/Source/core/frame/DOMWindow.cpp b/third_party/WebKit/Source/core/frame/DOMWindow.cpp
index 4e42da30fadd58788336bcc40100ec25761c1ac1..1c0aa0925a30e30562f87db1f14746598d686bd7 100644
--- a/third_party/WebKit/Source/core/frame/DOMWindow.cpp
+++ b/third_party/WebKit/Source/core/frame/DOMWindow.cpp
@@ -103,10 +103,7 @@ DOMWindow* DOMWindow::opener() const
 
 DOMWindow* DOMWindow::parent() const
 {
-    // TODO(yukishiino): The 'parent' attribute must return |this|
-    // (the WindowProxy object of the browsing context itself) when it's
-    // top-level or detached.
-    if (!isCurrentlyDisplayedInFrame())
+    if (!frame())
         return nullptr;
 
     Frame* parent = frame()->tree().parent();
@@ -115,10 +112,7 @@ DOMWindow* DOMWindow::parent() const
 
 DOMWindow* DOMWindow::top() const
 {
-    // TODO(yukishiino): The 'top' attribute must return |this|
-    // (the WindowProxy object of the browsing context itself) when it's
-    // top-level or detached.
-    if (!isCurrentlyDisplayedInFrame())
+    if (!frame())
         return nullptr;
 
     return frame()->tree().top()->domWindow();