Initial commit of sync engine code to browser/sync....

chrome/browser/sync/util/highres_timer-linux.cc

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// High resolution timer functions for use in Linux.
+
+#include "chrome/browser/sync/util/highres_timer.h"
+
+const uint64 MICROS_IN_MILLI = 1000L;
+const uint64 MICROS_IN_HALF_MILLI = 500L;
+const uint64 MICROS_IN_HALF_SECOND = 500000L;
+
+uint64 HighresTimer::GetElapsedMs() const {
+  uint64 end_time = GetCurrentTicks();
+
+  // Scale to ms and round to nearest ms - rounding is important because
+  // otherwise the truncation error may accumulate e.g. in sums.
+  return (uint64(end_time - start_ticks_) + MICROS_IN_HALF_MILLI) /
+             MICROS_IN_MILLI;
+}
+
+uint64 HighresTimer::GetElapsedSec() const {
+  uint64 end_time = GetCurrentTicks();
+
+  // Scale to ms and round to nearest ms - rounding is important because
+  // otherwise the truncation error may accumulate e.g. in sums.
+  return (uint64(end_time - start_ticks_) + MICROS_IN_HALF_SECOND) /
+             MICROS_IN_SECOND;
+}