ScriptState::contextIsEmpty shouldn't return true for a context whose global object is detached

Source/core/inspector/InspectorOverlay.cpp

Index: Source/core/inspector/InspectorOverlay.cpp
diff --git a/Source/core/inspector/InspectorOverlay.cpp b/Source/core/inspector/InspectorOverlay.cpp
index 5492252f41d193a4d6013440f386a5a5554920e4..215fcbe720f9affd6ee6e239274a4c5f95390cb6 100644
--- a/Source/core/inspector/InspectorOverlay.cpp
+++ b/Source/core/inspector/InspectorOverlay.cpp
@@ -745,7 +745,7 @@ Page* InspectorOverlay::overlayPage()
     loader.load(FrameLoadRequest(0, blankURL(), SubstituteData(data, "text/html", "UTF-8", KURL(), ForceSynchronousLoad)));
     v8::Isolate* isolate = toIsolate(frame.get());
     ScriptState* scriptState = ScriptState::forMainWorld(frame.get());
-    ASSERT(!scriptState->contextIsEmpty());
+    ASSERT(!scriptState->contextIsValid());
     ScriptState::Scope scope(scriptState);
     v8::Handle<v8::Object> global = scriptState->context()->Global();
     v8::Handle<v8::Value> overlayHostObj = toV8(m_overlayHost.get(), global, isolate);