Hook up TaskObserver and PowerObserver in GPU watchdog V2

Bug: 949839
Change-Id: I418e39d621ab7ab294fd00ee2618234341dbf287
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1661216
Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Maggie Chen <magchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#670341}

gpu/ipc/service/gpu_watchdog_thread_v2.cc

@@ -6,6 +6,8 @@
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/message_loop/message_loop_current.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 
@@ -23,13 +25,21 @@ const int kGpuTimeoutInMs = 10000;
 
 GpuWatchdogThreadImplV2::GpuWatchdogThreadImplV2()
     : timeout_(base::TimeDelta::FromMilliseconds(kGpuTimeoutInMs)),
-      task_observer_(this),
       watched_task_runner_(base::ThreadTaskRunnerHandle::Get()),
-      weak_factory_(this) {}
+      weak_factory_(this) {
+  Disarm();
+
+  base::MessageLoopCurrent::Get()->AddTaskObserver(this);
+}
 
 GpuWatchdogThreadImplV2::~GpuWatchdogThreadImplV2() {
   DCHECK(watched_task_runner_->BelongsToCurrentThread());
-  Stop();
+  Stop();  // stop the watchdog thread
+
+  base::MessageLoopCurrent::Get()->RemoveTaskObserver(this);
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  if (power_monitor)
+    power_monitor->RemoveObserver(this);
 }
 
 // static
@@ -46,7 +56,14 @@ std::unique_ptr<GpuWatchdogThreadImplV2> GpuWatchdogThreadImplV2::Create(
   return watchdog_thread;
 }
 
-void GpuWatchdogThreadImplV2::AddPowerObserver() {}
+// Do not add power observer during watchdog init, PowerMonitor might not be up
+// running yet.
+void GpuWatchdogThreadImplV2::AddPowerObserver() {
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  DCHECK(power_monitor);
+  if (power_monitor)
+    power_monitor->AddObserver(this);
+}
 
 void GpuWatchdogThreadImplV2::OnBackgrounded() {}
 
@@ -60,19 +77,14 @@ void GpuWatchdogThreadImplV2::CleanUp() {
   weak_factory_.InvalidateWeakPtrs();
 }
 
-GpuWatchdogThreadImplV2::GpuWatchdogTaskObserver::GpuWatchdogTaskObserver(
-    GpuWatchdogThreadImplV2* watchdog)
-    : watchdog_(watchdog) {}
-
-GpuWatchdogThreadImplV2::GpuWatchdogTaskObserver::~GpuWatchdogTaskObserver() =
-    default;
-
-void GpuWatchdogThreadImplV2::GpuWatchdogTaskObserver::WillProcessTask(
-    const base::PendingTask& pending_task) {}
+void GpuWatchdogThreadImplV2::WillProcessTask(
+    const base::PendingTask& pending_task) {
+  Arm();
+}
 
-void GpuWatchdogThreadImplV2::GpuWatchdogTaskObserver::DidProcessTask(
+void GpuWatchdogThreadImplV2::DidProcessTask(
     const base::PendingTask& pending_task) {
-  watchdog_->Disarm();
+  Disarm();
 }
 
 void GpuWatchdogThreadImplV2::Arm() {}

gpu/ipc/service/gpu_watchdog_thread_v2.h

@@ -10,7 +10,8 @@
 namespace gpu {
 
 class GPU_IPC_SERVICE_EXPORT GpuWatchdogThreadImplV2
-    : public GpuWatchdogThread {
+    : public GpuWatchdogThread,
+      public base::MessageLoopCurrent::TaskObserver {
  public:
   static std::unique_ptr<GpuWatchdogThreadImplV2> Create(
       bool start_backgrounded);
@@ -30,22 +31,6 @@ class GPU_IPC_SERVICE_EXPORT GpuWatchdogThreadImplV2
   void CleanUp() override;
 
  private:
-  // An object of this type intercepts the reception and completion of all tasks
-  // on the watched thread and checks whether the watchdog is armed.
-  class GpuWatchdogTaskObserver
-      : public base::MessageLoopCurrent::TaskObserver {
-   public:
-    explicit GpuWatchdogTaskObserver(GpuWatchdogThreadImplV2* watchdog);
-    ~GpuWatchdogTaskObserver() override;
-
-    // Implements MessageLoopCurrent::TaskObserver.
-    void WillProcessTask(const base::PendingTask& pending_task) override;
-    void DidProcessTask(const base::PendingTask& pending_task) override;
-
-   private:
-    GpuWatchdogThreadImplV2* watchdog_;
-  };
-
   GpuWatchdogThreadImplV2();
   void Arm();
   void Disarm();
@@ -54,11 +39,14 @@ class GPU_IPC_SERVICE_EXPORT GpuWatchdogThreadImplV2
   void OnSuspend() override;
   void OnResume() override;
 
+  // Implements MessageLoopCurrent::TaskObserver.
+  void WillProcessTask(const base::PendingTask& pending_task) override;
+  void DidProcessTask(const base::PendingTask& pending_task) override;
+
   // Implements GpuWatchdogThread
   void DeliberatelyTerminateToRecoverFromHang() override;
 
   base::TimeDelta timeout_;
-  GpuWatchdogTaskObserver task_observer_;
   scoped_refptr<base::SingleThreadTaskRunner> watched_task_runner_;
 
   base::WeakPtrFactory<GpuWatchdogThreadImplV2> weak_factory_;