Remove unnecessary isolate argument from some visitors

runtime/vm/object.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 4618 matching lines @@
     kPtrOffSize = 30,
   };
 
   class OptimizedBit : public BitField<int32_t, bool, kOptimizedBit, 1> {};
   class AliveBit : public BitField<int32_t, bool, kAliveBit, 1> {};
   class PtrOffBits :
       public BitField<int32_t, intptr_t, kPtrOffBit, kPtrOffSize> {};
 
   class SlowFindRawCodeVisitor : public FindObjectVisitor {
    public:
-    explicit SlowFindRawCodeVisitor(uword pc)
-        : FindObjectVisitor(Isolate::Current()), pc_(pc) { }
+    explicit SlowFindRawCodeVisitor(uword pc) : pc_(pc) { }
     virtual ~SlowFindRawCodeVisitor() { }
 
     // Check if object matches find condition.
     virtual bool FindObject(RawObject* obj) const;
 
    private:
     const uword pc_;
 
     DISALLOW_COPY_AND_ASSIGN(SlowFindRawCodeVisitor);
   };
@@ skipping 3765 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_