Revert "Fix tsan failure"

runtime/vm/stack_frame.h

 // Copyright (c) 2011, 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 RUNTIME_VM_STACK_FRAME_H_
 #define RUNTIME_VM_STACK_FRAME_H_
 
 #include "vm/allocation.h"
 #include "vm/object.h"
 #include "vm/stub_code.h"
@@ skipping 129 matching lines @@
 
   uword fp_;
   uword sp_;
   uword pc_;
   Thread* thread_;
 
   // The iterators FrameSetIterator and StackFrameIterator set the private
   // fields fp_ and sp_ when they return the respective frame objects.
   friend class FrameSetIterator;
   friend class StackFrameIterator;
-  friend class ProfilerDartStackWalker;
   DISALLOW_COPY_AND_ASSIGN(StackFrame);
 };
 
 
 // Exit frame is used to mark the transition from dart code into dart VM
 // runtime code.
 class ExitFrame : public StackFrame {
  public:
   bool IsValid() const { return sp() == 0; }
   bool IsDartFrame(bool validate = true) const { return false; }
@@ skipping 119 matching lines @@
   void SetupLastExitFrameData();
   void SetupNextExitFrameData();
 
   bool validate_;     // Validate each frame as we traverse the frames.
   EntryFrame entry_;  // Singleton entry frame returned by NextEntryFrame().
   ExitFrame exit_;    // Singleton exit frame returned by NextExitFrame().
   FrameSetIterator frames_;
   StackFrame* current_frame_;  // Points to the current frame in the iterator.
   Thread* thread_;
 
-  friend class ProfilerDartStackWalker;
   DISALLOW_COPY_AND_ASSIGN(StackFrameIterator);
 };
 
 
 // Iterator for iterating over all dart frames (skips over exit frames,
 // entry frames and stub frames).
 // A DartFrameIterator can be initialized with an isolate other than the
 // current thread's isolate. Because this is generally a bad idea,
 // it is only allowed on Windows- where it is needed for the profiler.
 // It is the responsibility of users of DartFrameIterator to ensure that the
@@ skipping 101 matching lines @@
 
 
 DART_FORCE_INLINE static uword LocalVarAddress(uword fp, intptr_t index) {
   return fp + LocalVarIndex(0, index) * kWordSize;
 }
 
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_STACK_FRAME_H_