Re-create ThroughputTracker when animation starts

ui::ThroughputTracker should not be reused. It DCHECKs when data
tracking overlaps and drop reports when it happens. This CL
changes to create a new ui::ThroughputTracker instance when the
hover card bubble animation starts.

This also fixes one crash that a browser window on external display
gets moved to internal display when disconnecting external
displays, where the Compositor becomes invalid.

Bug: 1060816, 1096840
Change-Id: I63b50279492fe2e464ed45efd7139e4cb8a43148
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2254698Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780479}

chrome/browser/ui/views/tabs/tab_hover_card_bubble_view.cc

@@ -51,6 +51,7 @@
 
 #if defined(OS_CHROMEOS)
 #include "ash/public/cpp/metrics_util.h"
+#include "base/optional.h"
 #endif
 
 namespace {
@@ -142,10 +143,6 @@ class TabHoverCardBubbleView::WidgetFadeAnimationDelegate
   explicit WidgetFadeAnimationDelegate(views::Widget* hover_card)
       : AnimationDelegateViews(hover_card->GetRootView()),
         widget_(hover_card),
-#if defined(OS_CHROMEOS)
-        throughput_tracker_(
-            hover_card->GetCompositor()->RequestNewThroughputTracker()),
-#endif
         fade_animation_(std::make_unique<gfx::LinearAnimation>(this)) {
   }
   ~WidgetFadeAnimationDelegate() override = default;
@@ -181,7 +178,9 @@ class TabHoverCardBubbleView::WidgetFadeAnimationDelegate
     fade_animation_ = std::make_unique<gfx::LinearAnimation>(this);
     fade_animation_->SetDuration(kFadeInDuration);
 #if defined(OS_CHROMEOS)
-    throughput_tracker_.Start(ash::metrics_util::ForSmoothness(
+    throughput_tracker_.emplace(
+        widget_->GetCompositor()->RequestNewThroughputTracker());
+    throughput_tracker_->Start(ash::metrics_util::ForSmoothness(
         base::BindRepeating(&RecordFadeInSmoothness)));
 #endif
     fade_animation_->Start();
@@ -196,7 +195,9 @@ class TabHoverCardBubbleView::WidgetFadeAnimationDelegate
     set_animation_state(FadeAnimationState::FADE_OUT);
     fade_animation_->SetDuration(kFadeOutDuration);
 #if defined(OS_CHROMEOS)
-    throughput_tracker_.Start(ash::metrics_util::ForSmoothness(
+    throughput_tracker_.emplace(
+        widget_->GetCompositor()->RequestNewThroughputTracker());
+    throughput_tracker_->Start(ash::metrics_util::ForSmoothness(
         base::BindRepeating(&RecordFadeOutSmoothness)));
 #endif
     fade_animation_->Start();
@@ -208,7 +209,7 @@ class TabHoverCardBubbleView::WidgetFadeAnimationDelegate
 
     fade_animation_->Stop();
 #if defined(OS_CHROMEOS)
-    throughput_tracker_.Cancel();
+    throughput_tracker_->Cancel();
 #endif
     set_animation_state(FadeAnimationState::IDLE);
     widget_->SetOpacity(1.0f);
@@ -236,14 +237,14 @@ class TabHoverCardBubbleView::WidgetFadeAnimationDelegate
   void AnimationEnded(const gfx::Animation* animation) override {
     AnimationProgressed(animation);
 #if defined(OS_CHROMEOS)
-    throughput_tracker_.Stop();
+    throughput_tracker_->Stop();
 #endif
     set_animation_state(FadeAnimationState::IDLE);
   }
 
   views::Widget* const widget_;
 #if defined(OS_CHROMEOS)
-  ui::ThroughputTracker throughput_tracker_;
+  base::Optional<ui::ThroughputTracker> throughput_tracker_;
 #endif
   std::unique_ptr<gfx::LinearAnimation> fade_animation_;
   FadeAnimationState animation_state_ = FadeAnimationState::IDLE;