Clean up CodeObservers

runtime/vm/code_observers.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_CODE_OBSERVERS_H_
 #define VM_CODE_OBSERVERS_H_
 
 #include "vm/globals.h"
+#include "vm/allocation.h"
 
 namespace dart {
 
 // Object observing code creation events. Used by external profilers and
 // debuggers to map address ranges to function names.
 class CodeObserver {
  public:
+  CodeObserver() { }
+
   virtual ~CodeObserver() { }
 
   // Returns true if this observer is active and should be notified
   // about newly created code objects.
   virtual bool IsActive() const = 0;
 
   // Notify code observer about a newly created code object with the
   // given properties.
   virtual void Notify(const char* name,
                       uword base,
                       uword prologue_offset,
                       uword size,
                       bool optimized) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CodeObserver);
 };
 
 
-class CodeObservers {
+class CodeObservers : public AllStatic {
  public:
   static void InitOnce();
 
   static void Register(CodeObserver* observer);
 
   // Notify all active code observers about a newly created code object.
   static void NotifyAll(const char* name,
                         uword base,
                         uword prologue_offset,
                         uword size,
                         bool optimized);
 
   // Returns true if there is at least one active code observer.
   static bool AreActive();
 
+  static void DeleteAll();
+
  private:
   static intptr_t observers_length_;
   static CodeObserver** observers_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_CODE_OBSERVERS_H_