Decouple root visitors from object visitors.

src/bootstrapper.h

 // Copyright 2014 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_BOOTSTRAPPER_H_
 #define V8_BOOTSTRAPPER_H_
 
 #include "src/factory.h"
 #include "src/snapshot/natives.h"
+#include "src/visitors.h"
 
 namespace v8 {
 namespace internal {
 
 // A SourceCodeCache uses a FixedArray to store pairs of
 // (OneByteString*, JSFunction*), mapping names of native code files
 // (array.js, etc.) to precompiled functions. Instead of mapping
 // names to functions it might make sense to let the JS2C tool
 // generate an index for each native JS file.
 class SourceCodeCache final BASE_EMBEDDED {
  public:
   explicit SourceCodeCache(Script::Type type): type_(type), cache_(NULL) { }
 
   void Initialize(Isolate* isolate, bool create_heap_objects) {
     cache_ = create_heap_objects ? isolate->heap()->empty_fixed_array() : NULL;
   }
 
-  void Iterate(ObjectVisitor* v) {
-    v->VisitPointer(bit_cast<Object**, FixedArray**>(&cache_));
+  void Iterate(RootVisitor* v) {
+    v->VisitRootPointer(Root::kExtensions,
+                        bit_cast<Object**, FixedArray**>(&cache_));
   }
 
   bool Lookup(Vector<const char> name, Handle<SharedFunctionInfo>* handle) {
     for (int i = 0; i < cache_->length(); i+=2) {
       SeqOneByteString* str = SeqOneByteString::cast(cache_->get(i));
       if (str->IsUtf8EqualTo(name)) {
         *handle = Handle<SharedFunctionInfo>(
             SharedFunctionInfo::cast(cache_->get(i + 1)));
         return true;
       }
@@ skipping 48 matching lines @@
       GlobalContextType context_type = FULL_CONTEXT);
 
   Handle<JSGlobalProxy> NewRemoteContext(
       MaybeHandle<JSGlobalProxy> maybe_global_proxy,
       v8::Local<v8::ObjectTemplate> global_object_template);
 
   // Detach the environment from its outer global object.
   void DetachGlobal(Handle<Context> env);
 
   // Traverses the pointers for memory management.
-  void Iterate(ObjectVisitor* v);
+  void Iterate(RootVisitor* v);
 
   // Accessor for the native scripts source code.
   Handle<String> GetNativeSource(NativeType type, int index);
 
   // Tells whether bootstrapping is active.
   bool IsActive() const { return nesting_ != 0; }
 
   // Support for thread preemption.
   static int ArchiveSpacePerThread();
   char* ArchiveState(char* to);
@@ skipping 52 matching lines @@
  private:
   Bootstrapper* bootstrapper_;
 
   DISALLOW_COPY_AND_ASSIGN(BootstrapperActive);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_BOOTSTRAPPER_H_