Revert of Do V8 GC ASAP if system memory is pressured

third_party/WebKit/Source/core/workers/WorkerBackingThread.h

 // Copyright 2016 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.
 
 #ifndef WorkerBackingThread_h
 #define WorkerBackingThread_h
 
 #include "core/CoreExport.h"
 #include "wtf/Forward.h"
 #include "wtf/OwnPtr.h"
@@ skipping 43 matching lines @@
     }
 
     WebThreadSupportingGC& backingThread()
     {
         DCHECK(m_backingThread);
         return *m_backingThread;
     }
 
     v8::Isolate* isolate() { return m_isolate; }
 
-    static void MemoryPressureNotificationToWorkerThreadIsolates(
-        v8::MemoryPressureLevel);
-
 private:
     WorkerBackingThread(const char* name, bool shouldCallGCOnShutdown);
     WorkerBackingThread(WebThread*, bool shouldCallGCOnSHutdown);
     void initialize();
     void shutdown();
 
     // Protects |m_workerScriptCount|.
     Mutex m_mutex;
     OwnPtr<WebThreadSupportingGC> m_backingThread;
     v8::Isolate* m_isolate = nullptr;
     unsigned m_workerScriptCount = 0;
     bool m_isOwningThread;
     bool m_shouldCallGCOnShutdown;
 };
 
 } // namespace blink
 
 #endif // WorkerBackingThread_h