Simplify timeline backend

runtime/vm/thread_registry.h

 // Copyright (c) 2015, 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_THREAD_REGISTRY_H_
 #define VM_THREAD_REGISTRY_H_
 
 #include "vm/globals.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
@@ skipping 170 matching lines @@
   // TODO(koda): Add method Monitor::IsOwnedByCurrentThread.
   Entry* FindEntry(Thread* thread) {
     for (int i = 0; i < entries_.length(); ++i) {
       if (entries_[i].thread == thread) {
         return &entries_[i];
       }
     }
     return NULL;
   }
 
-  // NOTE: Lock should be taken before this function is called.
-  void ReclaimTimelineBlockLocked(Entry* entry);
-
   // Note: Lock should be taken before this function is called.
   void CheckSafepointLocked();
 
   // Returns the number threads that are scheduled on this isolate.
   // Note: Lock should be taken before this function is called.
   intptr_t CountScheduledLocked();
 
   Monitor* monitor_;  // All access is synchronized through this monitor.
   MallocGrowableArray<Entry> entries_;
 
   // Safepoint rendezvous state.
   bool in_rendezvous_;    // A safepoint rendezvous request is in progress.
   intptr_t remaining_;    // Number of threads yet to reach their safepoint.
   int64_t round_;         // Counter, to prevent missing updates to remaining_
                           // (see comments in CheckSafepointLocked).
 
   DISALLOW_COPY_AND_ASSIGN(ThreadRegistry);
 };
 
 }  // namespace dart
 
 #endif  // VM_THREAD_REGISTRY_H_