Move policy code into components/policy.

chrome/browser/policy/cloud/rate_limiter.cc

-// Copyright (c) 2013 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.
-
-#include "chrome/browser/policy/cloud/rate_limiter.h"
-
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/location.h"
-#include "base/logging.h"
-#include "base/sequenced_task_runner.h"
-#include "base/time/tick_clock.h"
-
-namespace policy {
-
-RateLimiter::RateLimiter(size_t max_requests,
-                         const base::TimeDelta& duration,
-                         const base::Closure& callback,
-                         scoped_refptr<base::SequencedTaskRunner> task_runner,
-                         scoped_ptr<base::TickClock> clock)
-    : max_requests_(max_requests),
-      duration_(duration),
-      callback_(callback),
-      task_runner_(task_runner),
-      clock_(clock.Pass()) {
-  DCHECK_GT(max_requests_, 0u);
-}
-
-RateLimiter::~RateLimiter() {}
-
-void RateLimiter::PostRequest() {
-  DCHECK(CalledOnValidThread());
-
-  const base::TimeTicks now = clock_->NowTicks();
-  const base::TimeTicks period_start = now - duration_;
-  while (!invocation_times_.empty() &&
-         invocation_times_.front() <= period_start) {
-    invocation_times_.pop();
-  }
-
-  delayed_callback_.Cancel();
-
-  if (invocation_times_.size() < max_requests_) {
-    invocation_times_.push(now);
-    callback_.Run();
-  } else {
-    // From the while() loop above we have front() > period_start,
-    // so time_until_next_callback > 0.
-    const base::TimeDelta time_until_next_callback =
-        invocation_times_.front() - period_start;
-    delayed_callback_.Reset(
-        base::Bind(&RateLimiter::PostRequest, base::Unretained(this)));
-    task_runner_->PostDelayedTask(
-        FROM_HERE, delayed_callback_.callback(), time_until_next_callback);
-  }
-}
-
-}  // namespace policy