Cros splitscreen: Show minimized window before sending the state change notification.

Bug: 829092
Change-Id: Ibfe49a09148cfcd7b6fb489eadfbc5b43bb682ec
Reviewed-on: https://chromium-review.googlesource.com/996570Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548252}

ash/wm/tablet_mode/tablet_mode_window_manager_unittest.cc

@@ -1683,6 +1683,7 @@ class TestObserver : public wm::WindowStateObserver {
   void OnPostWindowStateTypeChange(wm::WindowState* window_state,
                                    mojom::WindowStateType old_type) override {
     post_count_++;
+    post_layer_visibility_ = window_state->window()->layer()->visible();
     EXPECT_EQ(last_old_state_, old_type);
   }
 
@@ -1698,6 +1699,12 @@ class TestObserver : public wm::WindowStateObserver {
     return r;
   }
 
+  bool GetPostLayerVisibilityAndReset() {
+    bool r = post_layer_visibility_;
+    post_layer_visibility_ = false;
+    return r;
+  }
+
   mojom::WindowStateType GetLastOldStateAndReset() {
     mojom::WindowStateType r = last_old_state_;
     last_old_state_ = mojom::WindowStateType::DEFAULT;
@@ -1707,6 +1714,7 @@ class TestObserver : public wm::WindowStateObserver {
  private:
   int pre_count_ = 0;
   int post_count_ = 0;
+  bool post_layer_visibility_ = false;
   mojom::WindowStateType last_old_state_ = mojom::WindowStateType::DEFAULT;
 
   DISALLOW_COPY_AND_ASSIGN(TestObserver);
@@ -1762,6 +1770,7 @@ TEST_F(TabletModeWindowManagerTest, StateTypeChange) {
   EXPECT_EQ(1, observer.GetPostCountAndReset());
   EXPECT_EQ(mojom::WindowStateType::MINIMIZED,
             observer.GetLastOldStateAndReset());
+  EXPECT_EQ(true, observer.GetPostLayerVisibilityAndReset());
 
   window_state->RemoveObserver(&observer);
 

ash/wm/tablet_mode/tablet_mode_window_state.cc

@@ -341,6 +341,14 @@ void TabletModeWindowState::UpdateWindow(wm::WindowState* window_state,
     UpdateBounds(window_state, animated);
   }
 
+  if ((window_state->window()->layer()->GetTargetVisibility() ||
+       old_state_type == mojom::WindowStateType::MINIMIZED) &&
+      !window_state->window()->layer()->visible()) {
+    // The layer may be hidden if the window was previously minimized. Make
+    // sure it's visible.
+    window_state->window()->Show();
+  }
+
   window_state->NotifyPostStateTypeChange(old_state_type);
 
   if (old_state_type == mojom::WindowStateType::PINNED ||
@@ -350,14 +358,6 @@ void TabletModeWindowState::UpdateWindow(wm::WindowState* window_state,
     Shell::Get()->screen_pinning_controller()->SetPinnedWindow(
         window_state->window());
   }
-
-  if ((window_state->window()->layer()->GetTargetVisibility() ||
-       old_state_type == mojom::WindowStateType::MINIMIZED) &&
-      !window_state->window()->layer()->visible()) {
-    // The layer may be hidden if the window was previously minimized. Make
-    // sure it's visible.
-    window_state->window()->Show();
-  }
 }
 
 mojom::WindowStateType TabletModeWindowState::GetMaximizedOrCenteredWindowType(