Remove unnecessary isolate argument from some visitors

runtime/vm/object_graph.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object_graph.h"
 
 #include "vm/dart.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 120 matching lines @@
     // Some internal VM objects visit pointers not contained within the parent.
     // For instance, RawCode::VisitCodePointers visits pointers in instructions.
     ASSERT(!parent.obj->IsDartInstance());
     return -1;
   }
 }
 
 
 class Unmarker : public ObjectVisitor {
  public:
-  explicit Unmarker(Isolate* isolate) : ObjectVisitor(isolate) { }
+  Unmarker() { }
 
   void VisitObject(RawObject* obj) {
     if (obj->IsMarked()) {
       obj->ClearMarkBit();
     }
   }
 
   static void UnmarkAll(Isolate* isolate) {
-    Unmarker unmarker(isolate);
+    Unmarker unmarker;
     isolate->heap()->IterateObjects(&unmarker);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Unmarker);
 };
 
 
 ObjectGraph::ObjectGraph(Thread* thread)
     : StackResource(thread) {
@@ skipping 24 matching lines @@
   Stack stack(isolate());
   RawObject* root_raw = root.raw();
   stack.VisitPointer(&root_raw);
   stack.TraverseGraph(visitor);
   Unmarker::UnmarkAll(isolate());
 }
 
 
 class InstanceAccumulator : public ObjectVisitor {
  public:
-  explicit InstanceAccumulator(ObjectGraph::Stack* stack,
-                               intptr_t class_id,
-                               Isolate* isolate)
-    : ObjectVisitor(isolate), stack_(stack), class_id_(class_id) { }
+  InstanceAccumulator(ObjectGraph::Stack* stack, intptr_t class_id)
+      : stack_(stack), class_id_(class_id) { }
 
   void VisitObject(RawObject* obj) {
     if (obj->GetClassId() == class_id_) {
       RawObject* rawobj = obj;
       stack_->VisitPointer(&rawobj);
     }
   }
 
  private:
   ObjectGraph::Stack* stack_;
   const intptr_t class_id_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceAccumulator);
 };
 
 
 void ObjectGraph::IterateObjectsFrom(intptr_t class_id,
                                      ObjectGraph::Visitor* visitor) {
   NoSafepointScope no_safepoint_scope_;
   Stack stack(isolate());
 
-  InstanceAccumulator accumulator(&stack, class_id, isolate());
+  InstanceAccumulator accumulator(&stack, class_id);
   isolate()->heap()->IterateObjects(&accumulator);
 
   stack.TraverseGraph(visitor);
   Unmarker::UnmarkAll(isolate());
 }
 
 
 class SizeVisitor : public ObjectGraph::Visitor {
  public:
   SizeVisitor() : size_(0) { }
@@ skipping 138 matching lines @@
 
 
 class InboundReferencesVisitor : public ObjectVisitor,
                                  public ObjectPointerVisitor {
  public:
   // We cannot use a GrowableObjectArray, since we must not trigger GC.
   InboundReferencesVisitor(Isolate* isolate,
                            RawObject* target,
                            const Array& references,
                            Object* scratch)
-    : ObjectVisitor(isolate), ObjectPointerVisitor(isolate), source_(NULL),
+    : ObjectPointerVisitor(isolate), source_(NULL),
       target_(target), references_(references), scratch_(scratch), length_(0) {
     ASSERT(Thread::Current()->no_safepoint_scope_depth() != 0);
   }
 
   intptr_t length() const { return length_; }
 
   virtual void VisitObject(RawObject* raw_obj) {
     source_ = raw_obj;
     raw_obj->VisitPointers(this);
   }
@@ skipping 136 matching lines @@
   {
     WritePointerVisitor ptr_writer(isolate(), stream);
     isolate()->IterateObjectPointers(&ptr_writer, false);
   }
   stream->WriteUnsigned(0);
   IterateObjects(&visitor);
   return visitor.count() + 1;  // + root
 }
 
 }  // namespace dart