[CacheStorage] Add metrics to the scheduler

content/browser/cache_storage/cache_storage_operation_unittest.cc

+// Copyright 2016 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 "content/browser/cache_storage/cache_storage_operation.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/run_loop.h"
+#include "base/test/histogram_tester.h"
+#include "base/test/test_mock_time_task_runner.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace content {
+
+namespace {
+
+const char kSlowOperation[] =
+    "ServiceWorkerCache.CacheStorage.Scheduler.IsOperationSlow";
+
+class TestTask {
+ public:
+  TestTask() = default;
+  ~TestTask() = default;
+  void Run() { callback_count_++; }
+
+  int callback_count() const { return callback_count_; }
+
+ protected:
+  int callback_count_ = 0;
+};
+
+}  // namespace
+
+class CacheStorageOperationTest : public testing::Test {
+ protected:
+  CacheStorageOperationTest()
+      : mock_task_runner_(new base::TestMockTimeTaskRunner()) {
+    operation_ = base::MakeUnique<CacheStorageOperation>(
+        base::Bind(&TestTask::Run, base::Unretained(&task_)),
+        CacheStorageSchedulerClient::CLIENT_STORAGE, mock_task_runner_);
+  }
+
+  base::HistogramTester histogram_tester_;
+  TestTask task_;
+  scoped_refptr<base::TestMockTimeTaskRunner> mock_task_runner_;
+  std::unique_ptr<CacheStorageOperation> operation_;
+};
+
+TEST_F(CacheStorageOperationTest, OperationFast) {
+  operation_->Run();
+  mock_task_runner_->RunUntilIdle();
+  EXPECT_EQ(1, task_.callback_count());
+  histogram_tester_.ExpectTotalCount(kSlowOperation, 0);
+
+  // Finish the operation.
+  operation_.reset();
+
+  mock_task_runner_->RunUntilIdle();
+  EXPECT_EQ(1, task_.callback_count());
+  histogram_tester_.ExpectTotalCount(kSlowOperation, 1);
+  histogram_tester_.ExpectBucketCount(kSlowOperation, false, 1);
+}
+
+TEST_F(CacheStorageOperationTest, OperationSlow) {
+  operation_->Run();
+  mock_task_runner_->RunUntilIdle();
+  EXPECT_EQ(1, task_.callback_count());
+  histogram_tester_.ExpectTotalCount(kSlowOperation, 0);
+
+  // The operation takes 10 seconds.
+  mock_task_runner_->FastForwardBy(base::TimeDelta::FromSeconds(10));
+  mock_task_runner_->RunUntilIdle();
+  histogram_tester_.ExpectTotalCount(kSlowOperation, 1);
+  histogram_tester_.ExpectBucketCount(kSlowOperation, true, 1);
+
+  // Finish the operation.
+  operation_.reset();
+  mock_task_runner_->RunUntilIdle();
+  EXPECT_EQ(1, task_.callback_count());
+  histogram_tester_.ExpectTotalCount(kSlowOperation, 1);
+  histogram_tester_.ExpectBucketCount(kSlowOperation, true, 1);
+}
+
+}  // namespace content