Revert of Implement suspend() and resume() for OfflineAudioContext

Source/modules/webaudio/DeferredTaskHandler.h

Index: Source/modules/webaudio/DeferredTaskHandler.h
diff --git a/Source/modules/webaudio/DeferredTaskHandler.h b/Source/modules/webaudio/DeferredTaskHandler.h
index c653ccb43fd27ab2116eee4c5d0f16c26506b731..b145642b82ea96eb3bd9de6e5d1ab3f3de8955c8 100644
--- a/Source/modules/webaudio/DeferredTaskHandler.h
+++ b/Source/modules/webaudio/DeferredTaskHandler.h
@@ -108,15 +108,8 @@
     bool isAudioThread() const { return currentThread() == acquireLoad(&m_audioThread); }
 
     void lock();
-
-    // This must be used only for OfflineAudioContext. It allows the regular
-    // lock (instead of tryLock) in offline audio rendering and it is okay to
-    // lock the offline audio render thread because it is not real-time thread.
-    void offlineContextLock();
-
     bool tryLock();
     void unlock();
-
 #if ENABLE(ASSERT)
     // Returns true if this thread owns the context's lock.
     bool isGraphOwner();