overview: Always animate unblur when exiting overview.

Test: manual
Bug: 833443
Change-Id: Iaf64e0c4edea2ae444d6d55a6103f922c5f33ffb
Reviewed-on: https://chromium-review.googlesource.com/1132476
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574950}

ash/wm/overview/window_selector.cc

@@ -661,13 +661,6 @@ bool WindowSelector::ShouldAnimateWallpaper(aura::Window* root_window) {
   if (!grid)
     return false;
 
-  // It is possible we leave overview mode to enter split view mode with both
-  // windows snapped. Do not animate the wallpaper in this case.
-  if (Shell::Get()->split_view_controller()->state() ==
-      SplitViewController::BOTH_SNAPPED) {
-    return false;
-  }
-
   // If one of the windows covers the workspace, we do not need to animate.
   for (const auto& selector_item : grid->window_list()) {
     if (CanCoverAvailableWorkspace(selector_item->GetWindow()))

ash/wm/overview/window_selector_controller.cc

@@ -32,6 +32,10 @@ namespace ash {
 
 namespace {
 
+// Do not blur or unblur the wallpaper when entering or exiting overview mode
+// when this is true.
+bool g_disable_wallpaper_blur_for_tests = false;
+
 // Amount of blur to apply on the wallpaper when we enter or exit overview mode.
 constexpr double kWallpaperBlurSigma = 10.f;
 constexpr double kWallpaperClearBlurSigma = 0.f;
@@ -71,7 +75,8 @@ bool ShouldExcludeWindowFromOverview(const aura::Window* window) {
 }
 
 bool IsBlurEnabled() {
-  return Shell::Get()->wallpaper_controller()->IsBlurEnabled();
+  return !g_disable_wallpaper_blur_for_tests &&
+         Shell::Get()->wallpaper_controller()->IsBlurEnabled();
 }
 
 }  // namespace
@@ -157,8 +162,9 @@ class WindowSelectorController::OverviewBlurController
   // |roots_to_animate_| accordingly. Applys blur or unblur immediately if
   // the wallpaper does not need blur animation.
   void OnBlurChange() {
-    bool should_blur = state_ == WallpaperAnimationState::kAddingBlur;
-    double value = should_blur ? kWallpaperBlurSigma : kWallpaperClearBlurSigma;
+    const bool should_blur = state_ == WallpaperAnimationState::kAddingBlur;
+    const double value =
+        should_blur ? kWallpaperBlurSigma : kWallpaperClearBlurSigma;
     for (aura::Window* root : roots_to_animate_)
       root->RemoveObserver(this);
     roots_to_animate_.clear();
@@ -166,17 +172,18 @@ class WindowSelectorController::OverviewBlurController
     WindowSelector* window_selector =
         Shell::Get()->window_selector_controller()->window_selector();
     DCHECK(window_selector);
+
     for (aura::Window* root : Shell::Get()->GetAllRootWindows()) {
-      if (!window_selector->ShouldAnimateWallpaper(root)) {
-        animation_.Reset(should_blur ? 1.0 : 0.0);
-        ApplyBlur(root, value);
-      } else {
+      if (!should_blur || window_selector->ShouldAnimateWallpaper(root)) {
         root->AddObserver(this);
         roots_to_animate_.push_back(root);
+      } else {
+        animation_.Reset(should_blur ? 1.0 : 0.0);
+        ApplyBlur(root, value);
       }
     }
 
-    // Run the animation if one of the roots needs to be aniamted.
+    // Run the animation if one of the roots needs to be animated.
     if (roots_to_animate_.empty()) {
       state_ = WallpaperAnimationState::kNormal;
     } else if (should_blur) {
@@ -438,6 +445,11 @@ void WindowSelectorController::RemoveAndDestroyAnimationObserver(
       delayed_animations_.end());
 }
 
+// static
+void WindowSelectorController::SetDoNotChangeWallpaperBlurForTests() {
+  g_disable_wallpaper_blur_for_tests = true;
+}
+
 void WindowSelectorController::OnSelectionStarted() {
   if (!last_selection_time_.is_null()) {
     UMA_HISTOGRAM_LONG_TIMES("Ash.WindowSelector.TimeBetweenUse",

ash/wm/overview/window_selector_controller.h

@@ -73,6 +73,9 @@ class ASH_EXPORT WindowSelectorController : public WindowSelectorDelegate {
   class OverviewBlurController;
   friend class WindowSelectorTest;
 
+  // There is no need to blur or unblur the wallpaper for tests.
+  static void SetDoNotChangeWallpaperBlurForTests();
+
   // Dispatched when window selection begins.
   void OnSelectionStarted();
 

ash/wm/overview/window_selector_unittest.cc

@@ -133,6 +133,7 @@ class WindowSelectorTest : public AshTestBase {
         GetPrimaryShelf()->GetShelfViewForTesting());
     shelf_view_test_api_->SetAnimationDuration(1);
     ScopedTransformOverviewWindow::SetImmediateCloseForTests();
+    WindowSelectorController::SetDoNotChangeWallpaperBlurForTests();
   }
 
   aura::Window* CreateWindow(const gfx::Rect& bounds) {