[scheduler] Monitor renderer load level.

third_party/WebKit/Source/platform/scheduler/base/thread_load_tracker_unittest.cc

Index: third_party/WebKit/Source/platform/scheduler/base/thread_load_tracker_unittest.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/base/thread_load_tracker_unittest.cc b/third_party/WebKit/Source/platform/scheduler/base/thread_load_tracker_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2315805c765e4f85823f8f9cb7038a9610bd0014
--- /dev/null
+++ b/third_party/WebKit/Source/platform/scheduler/base/thread_load_tracker_unittest.cc
@@ -0,0 +1,73 @@
+#include "platform/scheduler/base/thread_load_tracker.h"
+
+#include "base/bind.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace blink {
+namespace scheduler {
+
+namespace {
+
+void AddToVector(std::vector<std::pair<base::TimeTicks, double>>* vector,
+                 base::TimeTicks time,
+                 double load) {
+  vector->push_back({time, load});
+}
+
+base::TimeTicks SecondsToTime(int seconds) {
+  return base::TimeTicks() + base::TimeDelta::FromSeconds(seconds);
+}
+
+double Divide(int a, int b) {
+  return static_cast<double>(a) / b;
+}
+
+}  // namespace
+
+TEST(ThreadLoadTrackerTest, RecordTasks) {
+  std::vector<std::pair<base::TimeTicks, double>> result;
+
+  ThreadLoadTracker thread_load_tracker(
+      SecondsToTime(1), base::Bind(&AddToVector, base::Unretained(&result)));
+
+  thread_load_tracker.RecordTaskTime(SecondsToTime(3), SecondsToTime(5));
+  thread_load_tracker.RecordTaskTime(SecondsToTime(7), SecondsToTime(9));
+  thread_load_tracker.RecordTaskTime(SecondsToTime(10), SecondsToTime(13));
+  thread_load_tracker.RecordTaskTime(SecondsToTime(15), SecondsToTime(18));
+
+  // Because of 10-second delay we're getting information starting with 11s.
+  std::vector<std::pair<base::TimeTicks, double>> expected_result{
+      {SecondsToTime(11), Divide(5, 10)}, {SecondsToTime(12), Divide(6, 11)},
+      {SecondsToTime(13), Divide(7, 12)}, {SecondsToTime(14), Divide(7, 13)},
+      {SecondsToTime(15), Divide(7, 14)}, {SecondsToTime(16), Divide(8, 15)},
+      {SecondsToTime(17), Divide(9, 16)}, {SecondsToTime(18), Divide(10, 17)}};
+
+  EXPECT_EQ(result, expected_result);
+}
+
+TEST(ThreadLoadTrackerTest, PauseAndResume) {
+  std::vector<std::pair<base::TimeTicks, double>> result;
+
+  ThreadLoadTracker thread_load_tracker(
+      SecondsToTime(1), base::Bind(&AddToVector, base::Unretained(&result)));
+
+  thread_load_tracker.RecordTaskTime(SecondsToTime(3), SecondsToTime(4));
+  thread_load_tracker.Pause(SecondsToTime(5));
+  // This task should be ignored.
+  thread_load_tracker.RecordTaskTime(SecondsToTime(10), SecondsToTime(11));
+  thread_load_tracker.Resume(SecondsToTime(15));
+  // We're counting only last second.
+  thread_load_tracker.RecordTaskTime(SecondsToTime(14), SecondsToTime(16));
+  thread_load_tracker.RecordTaskTime(SecondsToTime(22), SecondsToTime(23));
+
+  std::vector<std::pair<base::TimeTicks, double>> expected_result{
+      {SecondsToTime(21), Divide(2, 10)},
+      {SecondsToTime(22), Divide(2, 11)},
+      {SecondsToTime(23), Divide(3, 12)}};
+
+  EXPECT_EQ(result, expected_result);
+}
+
+}  // namespace scheduler
+}  // namespace blink