Call LocalDOMWindow::clearDocument when a frame gets detached

third_party/WebKit/Source/bindings/core/v8/BindingSecurity.cpp

Index: third_party/WebKit/Source/bindings/core/v8/BindingSecurity.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/BindingSecurity.cpp b/third_party/WebKit/Source/bindings/core/v8/BindingSecurity.cpp
index e79f6af8840253391420cfec41c14d750513f20c..73c1fc776e973bba418446180faec88108f29ff6 100644
--- a/third_party/WebKit/Source/bindings/core/v8/BindingSecurity.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/BindingSecurity.cpp
@@ -215,8 +215,7 @@ bool BindingSecurity::shouldAllowAccessToDetachedWindow(
   CHECK(target && !target->frame())
       << "This version of shouldAllowAccessToFrame() must be used only for "
       << "detached windows.";
-  if (!target->document())
-    return false;
+  CHECK(target->document());
   return canAccessFrame(accessingWindow,
                         target->document()->getSecurityOrigin(), target,
                         exceptionState);