Revert of Added GetCpuTime to base/ to get total CPU time consumed by process for perf tests.

webrtc/base/cpu_time_unittest.cc

-/*
- *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#include <memory>
-#include <algorithm>
-#include "webrtc/base/cpu_time.h"
-#include "webrtc/base/platform_thread.h"
-#include "webrtc/base/timeutils.h"
-#include "webrtc/test/gtest.h"
-#include "webrtc/system_wrappers/include/cpu_info.h"
-
-namespace {
-const int kAllowedErrorMillisecs = 30;
-const int kProcessingTimeMillisecs = 300;
-
-// Consumes approximately kProcessingTimeMillisecs of CPU time.
-bool WorkingFunction(void* counter_pointer) {
-  int64_t* counter = reinterpret_cast<int64_t*>(counter_pointer);
-  *counter = 0;
-  int64_t stop_time = rtc::SystemTimeNanos() +
-                      kProcessingTimeMillisecs * rtc::kNumNanosecsPerMillisec;
-  while (rtc::SystemTimeNanos() < stop_time) {
-    (*counter)++;
-  }
-  return false;
-}
-}  // namespace
-
-namespace rtc {
-
-TEST(GetProcessCpuTimeTest, SingleThread) {
-  int64_t start_time_nanos = GetProcessCpuTimeNanos();
-  int64_t counter;
-  WorkingFunction(reinterpret_cast<void*>(&counter));
-  EXPECT_GT(counter, 0);
-  int64_t duration_nanos = GetProcessCpuTimeNanos() - start_time_nanos;
-  //  Should be about kProcessingTimeMillisecs.
-  EXPECT_NEAR(duration_nanos,
-              kProcessingTimeMillisecs * kNumNanosecsPerMillisec,
-              kAllowedErrorMillisecs * kNumNanosecsPerMillisec);
-}
-
-TEST(GetProcessCpuTimeTest, TwoThreads) {
-  int64_t start_time_nanos = GetProcessCpuTimeNanos();
-  int64_t counter1;
-  int64_t counter2;
-  PlatformThread thread1(WorkingFunction, reinterpret_cast<void*>(&counter1),
-                         "Thread1");
-  PlatformThread thread2(WorkingFunction, reinterpret_cast<void*>(&counter2),
-                         "Thread2");
-  thread1.Start();
-  thread2.Start();
-  thread1.Stop();
-  thread2.Stop();
-
-  EXPECT_GE(counter1, 0);
-  EXPECT_GE(counter2, 0);
-  int64_t duration_nanos = GetProcessCpuTimeNanos() - start_time_nanos;
-  const uint32_t kWorkingThreads = 2;
-  uint32_t used_cores =
-      std::min(webrtc::CpuInfo::DetectNumberOfCores(), kWorkingThreads);
-  // Two working threads for kProcessingTimeMillisecs consume double CPU time
-  // if there are at least 2 cores.
-  EXPECT_NEAR(duration_nanos,
-              used_cores * kProcessingTimeMillisecs * kNumNanosecsPerMillisec,
-              used_cores * kAllowedErrorMillisecs * kNumNanosecsPerMillisec);
-}
-
-TEST(GetThreadCpuTimeTest, SingleThread) {
-  int64_t start_times_nanos = GetThreadCpuTimeNanos();
-  int64_t counter;
-  WorkingFunction(reinterpret_cast<void*>(&counter));
-  EXPECT_GT(counter, 0);
-  int64_t duration_nanos = GetThreadCpuTimeNanos() - start_times_nanos;
-  EXPECT_NEAR(duration_nanos,
-              kProcessingTimeMillisecs * kNumNanosecsPerMillisec,
-              kAllowedErrorMillisecs * kNumNanosecsPerMillisec);
-}
-
-TEST(GetThreadCpuTimeTest, TwoThreads) {
-  int64_t start_time_nanos = GetThreadCpuTimeNanos();
-  int64_t counter1;
-  int64_t counter2;
-  PlatformThread thread1(WorkingFunction, reinterpret_cast<void*>(&counter1),
-                         "Thread1");
-  PlatformThread thread2(WorkingFunction, reinterpret_cast<void*>(&counter2),
-                         "Thread2");
-  thread1.Start();
-  thread2.Start();
-  thread1.Stop();
-  thread2.Stop();
-
-  EXPECT_GE(counter1, 0);
-  EXPECT_GE(counter2, 0);
-  int64_t duration_nanos = GetThreadCpuTimeNanos() - start_time_nanos;
-  // This thread didn't do any work.
-  EXPECT_NEAR(duration_nanos, 0,
-              kAllowedErrorMillisecs * kNumNanosecsPerMillisec);
-}
-
-}  // namespace rtc