Decouple root visitors from object visitors.

src/api.h

 // Copyright 2012 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_API_H_
 #define V8_API_H_
 
 #include "include/v8-testing.h"
 #include "src/contexts.h"
 #include "src/debug/debug-interface.h"
@@ skipping 351 matching lines @@
 
  private:
   DeferredHandles(Object** first_block_limit, Isolate* isolate)
       : next_(NULL),
         previous_(NULL),
         first_block_limit_(first_block_limit),
         isolate_(isolate) {
     isolate->LinkDeferredHandles(this);
   }
 
-  void Iterate(ObjectVisitor* v);
+  void Iterate(RootVisitor* v);
 
   List<Object**> blocks_;
   DeferredHandles* next_;
   DeferredHandles* previous_;
   Object** first_block_limit_;
   Isolate* isolate_;
 
   friend class HandleScopeImplementer;
   friend class Isolate;
 };
@@ skipping 31 matching lines @@
     DeleteArray(spare_);
   }
 
   // Threading support for handle data.
   static int ArchiveSpacePerThread();
   char* RestoreThread(char* from);
   char* ArchiveThread(char* to);
   void FreeThreadResources();
 
   // Garbage collection support.
-  void Iterate(v8::internal::ObjectVisitor* v);
-  static char* Iterate(v8::internal::ObjectVisitor* v, char* data);
-
+  void Iterate(v8::internal::RootVisitor* v);
+  static char* Iterate(v8::internal::RootVisitor* v, char* data);
 
   inline internal::Object** GetSpareOrNewBlock();
   inline void DeleteExtensions(internal::Object** prev_limit);
 
   // Call depth represents nested v8 api calls.
   inline void IncrementCallDepth() {call_depth_++;}
   inline void DecrementCallDepth() {call_depth_--;}
   inline bool CallDepthIsZero() { return call_depth_ == 0; }
 
   // Microtasks scope depth represents nested scopes controlling microtasks
@@ skipping 94 matching lines @@
   int microtasks_suppressions_;
   int entered_context_count_during_microtasks_;
 #ifdef DEBUG
   int debug_microtasks_depth_;
 #endif
   v8::MicrotasksPolicy microtasks_policy_;
   Object** last_handle_before_deferred_block_;
   // This is only used for threading support.
   HandleScopeData handle_scope_data_;
 
-  void IterateThis(ObjectVisitor* v);
+  void IterateThis(RootVisitor* v);
   char* RestoreThreadHelper(char* from);
   char* ArchiveThreadHelper(char* to);
 
   friend class DeferredHandles;
   friend class DeferredHandleScope;
 
   DISALLOW_COPY_AND_ASSIGN(HandleScopeImplementer);
 };
 
 
@@ skipping 117 matching lines @@
   }
 
  private:
   static v8::Testing::StressType stress_type_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_API_H_