Decouple root visitors from object visitors.

src/debug/debug.cc

 // 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.
 
 #include "src/debug/debug.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/arguments.h"
@@ skipping 399 matching lines @@
 
 
 char* Debug::RestoreDebug(char* storage) {
   // Simply reset state. Don't restore anything.
   ThreadInit();
   return storage + ArchiveSpacePerThread();
 }
 
 int Debug::ArchiveSpacePerThread() { return 0; }
 
-void Debug::Iterate(ObjectVisitor* v) {
-  v->VisitPointer(&thread_local_.return_value_);
-  v->VisitPointer(&thread_local_.suspended_generator_);
-  v->VisitPointer(&thread_local_.ignore_step_into_function_);
+void Debug::Iterate(RootVisitor* v) {
+  v->VisitRootPointer(Root::kDebug, &thread_local_.return_value_);
+  v->VisitRootPointer(Root::kDebug, &thread_local_.suspended_generator_);
+  v->VisitRootPointer(Root::kDebug, &thread_local_.ignore_step_into_function_);
 }
 
 DebugInfoListNode::DebugInfoListNode(DebugInfo* debug_info): next_(NULL) {
   // Globalize the request debug info object and make it weak.
   GlobalHandles* global_handles = debug_info->GetIsolate()->global_handles();
   debug_info_ = global_handles->Create(debug_info).location();
 }
 
 
 DebugInfoListNode::~DebugInfoListNode() {
@@ skipping 2061 matching lines @@
     isolate_->Throw(*isolate_->factory()->NewEvalError(
         MessageTemplate::kNoSideEffectDebugEvaluate));
   }
   isolate_->set_needs_side_effect_check(old_needs_side_effect_check_);
   isolate_->debug()->UpdateHookOnFunctionCall();
   isolate_->debug()->side_effect_check_failed_ = false;
 }
 
 }  // namespace internal
 }  // namespace v8