Add Function based profile tree

runtime/vm/signal_handler.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_SIGNAL_HANDLER_H_
 #define VM_SIGNAL_HANDLER_H_
 
 #include "vm/allocation.h"
 #include "vm/globals.h"
 
@@ skipping 30 matching lines @@
 typedef void (*SignalAction)(int signal, siginfo_t* info,
                              void* context);
 
 class SignalHandler : public AllStatic {
  public:
   static void Install(SignalAction action);
   static uintptr_t GetProgramCounter(const mcontext_t& mcontext);
   static uintptr_t GetFramePointer(const mcontext_t& mcontext);
   static uintptr_t GetCStackPointer(const mcontext_t& mcontext);
   static uintptr_t GetDartStackPointer(const mcontext_t& mcontext);
+  static uintptr_t GetLinkRegister(const mcontext_t& mcontext);
  private:
 };
 
 
 }  // namespace dart
 
 #endif  // VM_SIGNAL_HANDLER_H_