Do not change activation color on the frame during overview session.

I'll look into the paint issue with MirrorView separatgely,
but I think this is good change anyway because it can eliminate
activation animation when entering/exitting overview for performance.

Bug: 1083951
Test: manual see bug for repro step.

Change-Id: I02a9ed265b2ab36cf348b37937669777cfd76c41
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2523907
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825234}

ash/wm/overview/overview_controller.cc

@@ -368,6 +368,14 @@ void OverviewController::ToggleOverview(OverviewEnterExitType type) {
     DCHECK(CanEnterOverview());
     TRACE_EVENT_NESTABLE_ASYNC_BEGIN0("ui", "OverviewController::EnterOverview",
                                       this);
+    auto* active_window = window_util::GetActiveWindow();
+    if (active_window) {
+      auto* active_widget =
+          views::Widget::GetWidgetForNativeView(active_window);
+      if (active_widget)
+        paint_as_active_lock_ = active_widget->LockPaintAsActive();
+    }
+
     Shell::Get()->frame_throttling_controller()->StartThrottling(windows);
 
     // Clear any animations that may be running from last overview end.
@@ -517,15 +525,18 @@ void OverviewController::OnStartingAnimationComplete(bool canceled) {
 }
 
 void OverviewController::OnEndingAnimationComplete(bool canceled) {
+  for (auto& observer : observers_)
+    observer.OnOverviewModeEndingAnimationComplete(canceled);
+  UnpauseOcclusionTracker(occlusion_pause_duration_for_end_);
+
   // Unblur when animation is completed (or right away if there was no
   // delayed animation) unless it's canceled, in which case, we should keep
-  // the blur.
-  if (!canceled)
+  // the blur. Also resume the activation frame state.
+  if (!canceled) {
     overview_wallpaper_controller_->Unblur();
+    paint_as_active_lock_.reset();
+  }
 
-  for (auto& observer : observers_)
-    observer.OnOverviewModeEndingAnimationComplete(canceled);
-  UnpauseOcclusionTracker(occlusion_pause_duration_for_end_);
   TRACE_EVENT_NESTABLE_ASYNC_END1("ui", "OverviewController::ExitOverview",
                                   this, "canceled", canceled);
 }

ash/wm/overview/overview_controller.h

@@ -19,6 +19,7 @@
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "ui/aura/window_occlusion_tracker.h"
+#include "ui/views/widget/widget.h"
 
 namespace ash {
 
@@ -157,6 +158,8 @@ class ASH_EXPORT OverviewController : public OverviewDelegate,
 
   base::ObserverList<OverviewObserver> observers_;
 
+  std::unique_ptr<views::Widget::PaintAsActiveLock> paint_as_active_lock_;
+
   base::WeakPtrFactory<OverviewController> weak_ptr_factory_{this};
 
   DISALLOW_COPY_AND_ASSIGN(OverviewController);