Revert "[views] Eliminate OnWidgetClosing from NudgeWidgetObserver"

This reverts commit fe0287f.

Reason for revert: MSAN failure

https://ci.chromium.org/ui/p/chromium/builders/ci/Linux%20ChromiumOS%20MSan%20Tests/27901/overview?q=ExactID%3Aninja%3A%2F%2Fash%3Aash_unittests%2FAdaptiveChargingNudgeControllerTest.NudgeShowExactlyOnce+VHash%3Ab5761b05c7110eb2

Original change's description:
> [views] Eliminate OnWidgetClosing from NudgeWidgetObserver
>
> Favor OnWidgetDestroying over OnWidgetClosing. OnWidgetClosing is
> only called where a Widget is closed directly, it fails to catch
> the case when the system destroys the NativeWidget directly. This
> can result in UAFs in situations where the OS directly destroys
> the widget.
>
> OnWidgetDestroying will be called every time a widget is destroyed
> and should be used instead in most cases.
>
> Bug: 1240365
> Change-Id: I043635fcfcc9a52dd68b21f4f9c37539bc0d7f34
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3641295
> Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
> Commit-Queue: Thomas Lukaszewicz <tluk@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1002735}

Cq-Include-Trybots: luci.chromium.try:linux_chromium_chromeos_msan_rel_ng
Bug: 1240365
Change-Id: I69348c0efca1ffdd7362881489d2ee1b9631494f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3646362
Auto-Submit: Jeffrey Young <cowmoo@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Roman Arora <romanarora@google.com>
Reviewed-by: Thomas Lukaszewicz <tluk@chromium.org>
Commit-Queue: Roman Arora <romanarora@google.com>
Reviewed-by: Roman Arora <romanarora@google.com>
Cr-Commit-Position: refs/heads/main@{#1002911}

Author: Jeffrey Young

ash/system/power/adaptive_charging_nudge_controller_unittest.cc

@@ -32,13 +32,13 @@ class NudgeWidgetObserver : public views::WidgetObserver {
     widget_observation_.Observe(widget);
   }
 
-  void WaitForDestruction() {
+  void WaitForClose() {
     run_loop_ = std::make_unique<base::RunLoop>();
     run_loop_->Run();
   }
 
   // views::WidgetObserver:
-  void OnWidgetDestroying(views::Widget* widget) override {
+  void OnWidgetClosing(views::Widget* widget) override {
     if (run_loop_)
       run_loop_->Quit();
   }
@@ -75,8 +75,8 @@ class AdaptiveChargingNudgeControllerTest : public AshTestBase {
 
   AdaptiveChargingNudgeController* GetController() { return controller_.get(); }
 
-  void WaitForWidgetDestruction(AdaptiveChargingNudgeController* controller,
-                                SystemNudge* nudge) {
+  void WaitForWidgetClose(AdaptiveChargingNudgeController* controller,
+                          SystemNudge* nudge) {
     views::Widget* nudge_widget = nudge->widget();
     ASSERT_TRUE(nudge_widget);
     EXPECT_FALSE(nudge_widget->IsClosed());
@@ -86,12 +86,12 @@ class AdaptiveChargingNudgeControllerTest : public AshTestBase {
         ui::ScopedAnimationDurationScaleMode::SLOW_DURATION);
 
     // Pretend the hide nudge timer has elapsed.
-    NudgeWidgetObserver widget_destruction_observer(nudge_widget);
+    NudgeWidgetObserver widget_close_observer(nudge_widget);
     controller->FireHideNudgeTimerForTesting();
 
     EXPECT_TRUE(nudge_widget->GetLayer()->GetAnimator()->is_animating());
 
-    widget_destruction_observer.WaitForDestruction();
+    widget_close_observer.WaitForClose();
   }
 
  private:
@@ -109,7 +109,7 @@ TEST_F(AdaptiveChargingNudgeControllerTest, ShowsAndHidesNudge) {
   SystemNudge* nudge = controller->GetSystemNudgeForTesting();
   ASSERT_TRUE(nudge);
 
-  WaitForWidgetDestruction(controller, nudge);
+  WaitForWidgetClose(controller, nudge);
 }
 
 TEST_F(AdaptiveChargingNudgeControllerTest, NoNudgeShowForDisabledFeature) {
@@ -135,7 +135,7 @@ TEST_F(AdaptiveChargingNudgeControllerTest, NudgeShowExactlyOnce) {
   controller->GetNudgeDelayTimerForTesting()->FireNow();
   SystemNudge* nudge1 = controller->GetSystemNudgeForTesting();
   ASSERT_TRUE(nudge1);
-  WaitForWidgetDestruction(controller, nudge1);
+  WaitForWidgetClose(controller, nudge1);
 
   // No nudge for the second time.
   controller->ShowNudge();