Buffer cross frame paint timing updates.

chrome/common/page_load_metrics/test/weak_mock_timer.h

+// Copyright 2017 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.
+
+#ifndef CHROME_COMMON_PAGE_LOAD_METRICS_TEST_WEAK_MOCK_TIMER_H_
+#define CHROME_COMMON_PAGE_LOAD_METRICS_TEST_WEAK_MOCK_TIMER_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/timer/mock_timer.h"
+
+namespace page_load_metrics {
+namespace test {
+
+// WeakMockTimer is a MockTimer that allows clients to keep WeakPtr<>s to it.
+class WeakMockTimer : public base::MockTimer,
+                      public base::SupportsWeakPtr<WeakMockTimer> {
+ public:
+  WeakMockTimer();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WeakMockTimer);
+};
+
+// WeakMockTimerProvider is a testing helper class that test classes can inherit
+// from to provide basic MockTimer tracking capabilities.
+class WeakMockTimerProvider {
+ public:
+  WeakMockTimerProvider();
+  virtual ~WeakMockTimerProvider();
+
+  base::MockTimer* GetMockTimer() const;
+  void SetMockTimer(base::WeakPtr<WeakMockTimer> timer);
+
+ private:
+  base::WeakPtr<WeakMockTimer> timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(WeakMockTimerProvider);
+};
+
+}  // namespace test
+}  // namespace page_load_metrics
+
+#endif  // CHROME_COMMON_PAGE_LOAD_METRICS_TEST_WEAK_MOCK_TIMER_H_