ash: Restore previous show state after exiting fullscreen.

ash/common/wm/default_state.cc

Index: ash/common/wm/default_state.cc
diff --git a/ash/common/wm/default_state.cc b/ash/common/wm/default_state.cc
index e15f8884219b42d63652ccfadef7671c9e3e60e4..ba1b01ff136890b59d162c8a1c9bd3aa4fdb6a3f 100644
--- a/ash/common/wm/default_state.cc
+++ b/ash/common/wm/default_state.cc
@@ -767,9 +767,27 @@ void DefaultState::UpdateBoundsFromState(WindowState* window_state,
     }
   }
 
+  if (window_state->IsFullscreen()) {
+    // Save the previous show state so that we can correctly restore it after
+    // exiting the fullscreen mode.
+    auto previous_ui_state_type = ToWindowShowState(previous_state_type);
+    if (previous_ui_state_type == ui::SHOW_STATE_MINIMIZED) {
+      // If the previous show state is ui::SHOW_STATE_MINIMIZED, we will use
+      // the show state before the window was minimized. But if the window
+      // was fullscreen before it was minimized, we will keep the
+      // PreFullscreenShowStat unchanged.
+      previous_ui_state_type = window->GetPreMinimizedShowState();
+      if (previous_ui_state_type != ui::SHOW_STATE_FULLSCREEN)
+        window->SetPreFullscreenShowState(previous_ui_state_type);
+    } else {
+      window->SetPreFullscreenShowState(previous_ui_state_type);
+    }
+  }
+
   if (window_state->IsMinimized()) {
-    // Save the previous show state so that we can correctly restore it.
-    window->SetRestoreShowState(ToWindowShowState(previous_state_type));
+    // Save the previous show state so that we can correctly restore it after
+    // exiting the minimized mode.
+    window->SetPreMinimizedShowState(ToWindowShowState(previous_state_type));
     window->SetVisibilityAnimationType(
         WINDOW_VISIBILITY_ANIMATION_TYPE_MINIMIZE);