Remove support for object grouping during Garbage Collection

runtime/vm/isolate.h

 // Copyright (c) 2013, 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_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 103 matching lines @@
     return thread == NULL ? NULL : thread->isolate();
   }
 
   // Register a newly introduced class.
   void RegisterClass(const Class& cls);
   void RegisterClassAt(intptr_t index, const Class& cls);
   void ValidateClassTable();
 
   // Visit all object pointers.
   void IterateObjectPointers(ObjectPointerVisitor* visitor,
-                             bool visit_prologue_weak_persistent_handles,
                              bool validate_frames);
 
   // Visits weak object pointers.
-  void VisitWeakPersistentHandles(HandleVisitor* visitor,
-                                  bool visit_prologue_weak_persistent_handles);
-  void VisitPrologueWeakPersistentHandles(HandleVisitor* visitor);
+  void VisitWeakPersistentHandles(HandleVisitor* visitor);
 
   StoreBuffer* store_buffer() { return store_buffer_; }
 
   ThreadRegistry* thread_registry() { return thread_registry_; }
 
   ClassTable* class_table() { return &class_table_; }
   static intptr_t class_table_offset() {
     return OFFSET_OF(Isolate, class_table_);
   }
 
@@ skipping 546 matching lines @@
   void LowLevelShutdown();
   void Shutdown();
 
   void BuildName(const char* name_prefix);
   void PrintInvokedFunctions();
 
   void ProfileIdle();
 
   // Visit all object pointers. Caller must ensure concurrent sweeper is not
   // running, and the visitor must not allocate.
-  void VisitObjectPointers(ObjectPointerVisitor* visitor,
-                           bool visit_prologue_weak_persistent_handles,
-                           bool validate_frames);
+  void VisitObjectPointers(ObjectPointerVisitor* visitor, bool validate_frames);
 
   void set_user_tag(uword tag) {
     user_tag_ = tag;
   }
 
   RawGrowableObjectArray* GetAndClearPendingServiceExtensionCalls();
   RawGrowableObjectArray* pending_service_extension_calls() const {
     return pending_service_extension_calls_;
   }
   void set_pending_service_extension_calls(const GrowableObjectArray& value);
@@ skipping 288 matching lines @@
   uint8_t* serialized_message_;
   intptr_t serialized_message_len_;
   Isolate::Flags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_