[api] Remove marking persistents as partially dependent

src/global-handles.h

 // Copyright 2011 the V8 project 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 V8_GLOBAL_HANDLES_H_
 #define V8_GLOBAL_HANDLES_H_
 
 #include "include/v8.h"
 #include "include/v8-profiler.h"
 
@@ skipping 149 matching lines @@
   void ResetNumberOfPhantomHandleResets() {
     number_of_phantom_handle_resets_ = 0;
   }
 
   // Clear the weakness of a global handle.
   static void* ClearWeakness(Object** location);
 
   // Mark the reference to this object independent of any object group.
   static void MarkIndependent(Object** location);
 
-  // Mark the reference to this object externaly unreachable.
-  static void MarkPartiallyDependent(Object** location);
-
   static bool IsIndependent(Object** location);
 
   // Tells whether global handle is near death.
   static bool IsNearDeath(Object** location);
 
   // Tells whether global handle is weak.
   static bool IsWeak(Object** location);
 
   // Process pending weak handles.
   // Returns the number of freed nodes.
@@ skipping 273 matching lines @@
   int singleton_handles_[NUMBER_OF_SINGLETON_HANDLES];
 
   DISALLOW_COPY_AND_ASSIGN(EternalHandles);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_GLOBAL_HANDLES_H_