Revert "base/power_monitor: Add method to query thermal state"

This reverts commit 1e56c551.

Reason for revert: Broke compile on Mac Builder (dbg)

Failure
Step compile failed. Error logs are shown below:
[724/7143] CXX obj/base/base_unittests/power_monitor_device_source_unittest.o
FAILED: obj/base/base_unittests/power_monitor_device_source_unittest.o
/b/s/w/ir/cache/goma/client/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF...(too long)
../../base/power_monitor/power_monitor_device_source_unittest.cc:32:3: error: use of undeclared identifier 'DVLOG'
DVLOG(1) << PowerMonitorSource::DeviceThermalStateToString(current_state);
^
1 error generated.
More information in raw_io.output[failure_summary]

Original change's description:
> base/power_monitor: Add method to query thermal state
> 
> wip wip
> 
> Add PowerMonitor::GetCurrentThermalState()
> 
> Bug: 1071431
> Change-Id: Id3083e06f16fd2f05e685e77ddee94e274158758
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2248729
> Reviewed-by: Henrik Boström <hbos@chromium.org>
> Reviewed-by: François Doray <fdoray@chromium.org>
> Commit-Queue: Miguel Casas <mcasas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#781322}

TBR=fdoray@chromium.org,mcasas@chromium.org,hbos@chromium.org

Change-Id: I54bbdc02423890b8443cb2f1deec909b68d87ebf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1071431
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2260792Reviewed-by: Chris Sharp <csharp@chromium.org>
Commit-Queue: Chris Sharp <csharp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781325}

base/BUILD.gn

@@ -2743,7 +2743,6 @@ test("base_unittests") {
     "parameter_pack_unittest.cc",
     "path_service_unittest.cc",
     "pickle_unittest.cc",
-    "power_monitor/power_monitor_device_source_unittest.cc",
     "power_monitor/power_monitor_unittest.cc",
     "process/environment_internal_unittest.cc",
     "process/memory_unittest.cc",

base/power_monitor/power_monitor.cc

@@ -52,11 +52,6 @@ bool PowerMonitor::IsProcessSuspended() {
   return g_is_process_suspended.load(std::memory_order_relaxed);
 }
 
-PowerObserver::DeviceThermalState PowerMonitor::GetCurrentThermalState() {
-  DCHECK(IsInitialized());
-  return GetInstance()->source_->GetCurrentThermalState();
-}
-
 void PowerMonitor::NotifyPowerStateChange(bool battery_in_use) {
   DCHECK(IsInitialized());
   DVLOG(1) << "PowerStateChange: " << (battery_in_use ? "On" : "Off")

base/power_monitor/power_monitor.h

@@ -56,10 +56,6 @@ class BASE_EXPORT PowerMonitor {
   // what is the real power state.
   static bool IsProcessSuspended();
 
-  // Read the current DeviceThermalState if known. Can be called on any thread.
-  // May only be called if the PowerMonitor has been initialized.
-  static PowerObserver::DeviceThermalState GetCurrentThermalState();
-
   // Uninitializes the PowerMonitor. Should be called at the end of any unit
   // test that mocks out the PowerMonitor, to avoid affecting subsequent tests.
   // There must be no live PowerObservers when invoked. Safe to call even if the

base/power_monitor/power_monitor_device_source.h

@@ -47,8 +47,6 @@ class BASE_EXPORT PowerMonitorDeviceSource : public PowerMonitorSource {
 #endif
 
  private:
-  friend class PowerMonitorDeviceSourceTest;
-
 #if defined(OS_WIN)
   // Represents a message-only window for power message handling on Windows.
   // Only allow PowerMonitor to create it.
@@ -88,9 +86,6 @@ class BASE_EXPORT PowerMonitorDeviceSource : public PowerMonitorSource {
   bool IsOnBatteryPowerImpl() override;
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
-  // PowerMonitorSource:
-  PowerObserver::DeviceThermalState GetCurrentThermalState() override;
-
   // Reference to the system IOPMrootDomain port.
   io_connect_t power_manager_port_ = IO_OBJECT_NULL;
 

base/power_monitor/power_monitor_device_source_mac.mm

@@ -51,14 +51,6 @@ bool PowerMonitorDeviceSource::IsOnBatteryPowerImpl() {
   return true;
 }
 
-PowerObserver::DeviceThermalState
-PowerMonitorDeviceSource::GetCurrentThermalState() {
-  if (@available(macOS 10.10.3, *)) {
-    return thermal_state_observer_->GetCurrentThermalState();
-  };
-  return PowerObserver::DeviceThermalState::kUnknown;
-}
-
 namespace {
 
 void BatteryEventCallback(void*) {

base/power_monitor/power_monitor_device_source_unittest.cc

-// Copyright 2020 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 "base/power_monitor/power_monitor_device_source.h"
-
-#include "base/power_monitor/power_monitor.h"
-#include "base/power_monitor/power_monitor_source.h"
-#include "build/build_config.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-using DeviceThermalState = base::PowerObserver::DeviceThermalState;
-
-namespace base {
-
-class PowerMonitorDeviceSourceTest : public testing::Test {
- public:
-  PowerMonitorDeviceSourceTest() = default;
-  ~PowerMonitorDeviceSourceTest() override = default;
-
-  DeviceThermalState GetCurrentThermalState() {
-    return power_monitor_device_source_.GetCurrentThermalState();
-  }
-
-  PowerMonitorDeviceSource power_monitor_device_source_;
-};
-
-TEST_F(PowerMonitorDeviceSourceTest, GetCurrentThermalState) {
-  const DeviceThermalState current_state = GetCurrentThermalState();
-#if defined(OS_MACOSX) && !defined(OS_IOS)
-  // We cannot make assumptions on |current_state|. Print it out to use the var.
-  DVLOG(1) << PowerMonitorSource::DeviceThermalStateToString(current_state);
-#else
-  EXPECT_EQ(current_state, DeviceThermalState::kUnknown);
-#endif
-}
-
-}  // namespace base

base/power_monitor/power_monitor_source.cc

@@ -17,10 +17,6 @@ bool PowerMonitorSource::IsOnBatteryPower() {
   return on_battery_power_;
 }
 
-PowerObserver::DeviceThermalState PowerMonitorSource::GetCurrentThermalState() {
-  return PowerObserver::DeviceThermalState::kUnknown;
-}
-
 // static
 void PowerMonitorSource::ProcessPowerEvent(PowerEvent event_id) {
   if (!PowerMonitor::IsInitialized())

base/power_monitor/power_monitor_source.h

@@ -31,10 +31,6 @@ class BASE_EXPORT PowerMonitorSource {
   // Is the computer currently on battery power. Can be called on any thread.
   bool IsOnBatteryPower();
 
-  // Reads the current DeviceThermalState, if available on the platform.
-  // Otherwise, returns kUnknown.
-  virtual PowerObserver::DeviceThermalState GetCurrentThermalState();
-
   static const char* DeviceThermalStateToString(
       PowerObserver::DeviceThermalState state);
 

base/power_monitor/power_monitor_unittest.cc

@@ -102,7 +102,6 @@ TEST_F(PowerMonitorTest, ThermalThrottling) {
 
   for (const auto state : kThermalStates) {
     source()->GenerateThermalThrottlingEvent(state);
-    EXPECT_EQ(state, source()->GetCurrentThermalState());
     EXPECT_EQ(observer.last_thermal_state(), state);
   }
 

base/power_monitor/thermal_state_observer_mac.h

@@ -14,9 +14,9 @@
 
 namespace base {
 
-// This class is used to listen for the thermal state change notification
-// NSProcessInfoThermalStateDidChangeNotification, routing it to
-// PowerMonitorSource.
+// This class is used to listen for the thermal state change notification from
+// NSProcessInfoThermalStateDidChangeNotification via a fully owned
+// ThermalStateObserverDelegate, routing the notification to PowerMonitorSource.
 class BASE_EXPORT ThermalStateObserverMac {
  public:
   using StateUpdateCallback =
@@ -25,8 +25,6 @@ class BASE_EXPORT ThermalStateObserverMac {
   explicit ThermalStateObserverMac(StateUpdateCallback state_update_callback);
   ~ThermalStateObserverMac();
 
-  PowerObserver::DeviceThermalState GetCurrentThermalState();
-
  private:
   FRIEND_TEST_ALL_PREFIXES(ThermalStateObserverMacTest, StateChange);
   PowerObserver::DeviceThermalState state_for_testing_ =

base/power_monitor/thermal_state_observer_mac.mm

@@ -63,13 +63,4 @@ ThermalStateObserverMac::~ThermalStateObserverMac() {
   [[NSNotificationCenter defaultCenter]
       removeObserver:thermal_state_update_observer_];
 }
-
-PowerObserver::DeviceThermalState
-ThermalStateObserverMac::GetCurrentThermalState() NS_AVAILABLE_MAC(10_10_3) {
-  if (state_for_testing_ != PowerObserver::DeviceThermalState::kUnknown)
-    return state_for_testing_;
-  NSProcessInfoThermalState nsinfo_state =
-      [[NSProcessInfo processInfo] thermalState];
-  return NSProcessInfoThermalStateToDeviceThermalState(nsinfo_state);
-}
 }

base/test/power_monitor_test_base.cc

@@ -11,18 +11,14 @@
 
 namespace base {
 
-PowerMonitorTestSource::PowerMonitorTestSource() {
+PowerMonitorTestSource::PowerMonitorTestSource()
+    : test_on_battery_power_(false) {
   DCHECK(MessageLoopCurrent::Get())
       << "PowerMonitorTestSource requires a MessageLoop.";
 }
 
 PowerMonitorTestSource::~PowerMonitorTestSource() = default;
 
-PowerObserver::DeviceThermalState
-PowerMonitorTestSource::GetCurrentThermalState() {
-  return current_thermal_state_;
-}
-
 void PowerMonitorTestSource::GeneratePowerStateEvent(bool on_battery_power) {
   test_on_battery_power_ = on_battery_power;
   ProcessPowerEvent(POWER_STATE_EVENT);
@@ -46,7 +42,6 @@ bool PowerMonitorTestSource::IsOnBatteryPowerImpl() {
 void PowerMonitorTestSource::GenerateThermalThrottlingEvent(
     PowerObserver::DeviceThermalState new_thermal_state) {
   ProcessThermalEvent(new_thermal_state);
-  current_thermal_state_ = new_thermal_state;
   RunLoop().RunUntilIdle();
 }
 

base/test/power_monitor_test_base.h

@@ -14,7 +14,6 @@ class PowerMonitorTestSource : public PowerMonitorSource {
  public:
   PowerMonitorTestSource();
   ~PowerMonitorTestSource() override;
-  PowerObserver::DeviceThermalState GetCurrentThermalState() override;
 
   void GeneratePowerStateEvent(bool on_battery_power);
   void GenerateSuspendEvent();
@@ -25,9 +24,7 @@ class PowerMonitorTestSource : public PowerMonitorSource {
  protected:
   bool IsOnBatteryPowerImpl() override;
 
-  bool test_on_battery_power_ = false;
-  PowerObserver::DeviceThermalState current_thermal_state_ =
-      PowerObserver::DeviceThermalState::kUnknown;
+  bool test_on_battery_power_;
 };
 
 class PowerMonitorTestObserver : public PowerObserver {