Revert of Move the event attach/detach logic on unload from event.js to

extensions/renderer/script_context_set_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_loop/message_loop.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/features/feature.h"
 #include "extensions/renderer/script_context.h"
 #include "extensions/renderer/script_context_set.h"
 #include "gin/public/context_holder.h"
@@ skipping 35 matching lines @@
   // GetAll() returns a copy so removing from one should not remove from others.
   ScriptContextSet::ContextSet set_copy = context_set.GetAll();
   EXPECT_EQ(1u, set_copy.count(context));
 
   context_set.Remove(context);
   EXPECT_EQ(0, context_set.size());
   EXPECT_FALSE(context_set.GetByV8Context(context->v8_context()));
   EXPECT_EQ(1u, set_copy.size());
 
   // After removal, the context should be marked for destruction.
-  EXPECT_FALSE(context->is_valid());
+  EXPECT_FALSE(context->web_frame());
 
   // Run loop to do the actual deletion.
   loop.RunUntilIdle();
 }
 
 }  // namespace extensions