- Remove unused Counters class from isolate.

runtime/vm/counters.h

-// Copyright (c) 2014, 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_COUNTERS_H_
-#define VM_COUNTERS_H_
-
-#include "platform/assert.h"
-
-namespace dart {
-
-struct Counter {
-  Counter() : name(NULL), value(0) {}
-  const char* name;
-  int64_t value;
-};
-
-
-// Light-weight stats counters for temporary experiments/debugging.
-// A single statement is enough to add a counter:
-//   ...
-//   Isolate::Current()->counters()->Increment("allocated", size_in_bytes);
-//   ...
-class Counters {
- public:
-  Counters() : collision_(false) {}
-
-  // Adds 'delta' to the named counter. 'name' must be a literal string.
-  void Increment(const char* name, int64_t delta) {
-    Counter& counter =
-      counters_[reinterpret_cast<uword>(name) & (kSize - 1)];
-    if (counter.name != name && counter.name != NULL) {
-      collision_ = true;
-    }
-    counter.name = name;
-    counter.value += delta;
-  }
-
-  // Prints all counters to stderr.
-  ~Counters();
-
- private:
-  enum { kSize = 1024 };
-  COMPILE_ASSERT((0 == (kSize & (kSize - 1))));  // kSize is a power of 2.
-  Counter counters_[kSize];
-  bool collision_;
-};
-
-}  // namespace dart
-
-#endif  // VM_COUNTERS_H_