Fixes bug where shelf items could be added for children windows

WindowObserver::OnWindowVisibilityChanged() is called any time the
visibility of a descendant changes. This means if the visibility of a
child of a window shown on the shelf changes and the child's type is other
than none, then an entry is added to the shelf. I don't believe this would
happen for aura, but for mus the default type is TYPE_APP (unless
explicitly set).

BUG=none
TEST=covered by test
R=msw@chromium.org

Review-Url: https://codereview.chromium.org/2576023002
Cr-Commit-Position: refs/heads/master@{#438622}

ash/common/shelf/shelf_window_watcher.cc

@@ -100,6 +100,11 @@ void ShelfWindowWatcher::UserWindowObserver::OnWindowDestroying(
 void ShelfWindowWatcher::UserWindowObserver::OnWindowVisibilityChanged(
     WmWindow* window,
     bool visible) {
+  // OnWindowVisibilityChanged() is called for descendants too. We only care
+  // about changes to the visibility of windows we know about.
+  if (!window_watcher_->observed_user_windows_.IsObserving(window))
+    return;
+
   // The tooltip behavior for panel windows depends on the panel visibility.
   window_watcher_->OnUserWindowPropertyChanged(window);
 }

ash/common/shelf/shelf_window_watcher_unittest.cc

@@ -307,4 +307,30 @@ TEST_F(ShelfWindowWatcherTest, PanelWindow) {
   EXPECT_EQ(1, model_->item_count());
 }
 
+TEST_F(ShelfWindowWatcherTest, DontCreateShelfEntriesForChildWindows) {
+  const int initial_item_count = model_->item_count();
+
+  WmWindow* window = WmShell::Get()->NewWindow(ui::wm::WINDOW_TYPE_NORMAL,
+                                               ui::LAYER_NOT_DRAWN);
+  window->SetIntProperty(WmWindowProperty::SHELF_ITEM_TYPE, TYPE_APP);
+  WmShell::Get()
+      ->GetPrimaryRootWindow()
+      ->GetChildByShellWindowId(kShellWindowId_DefaultContainer)
+      ->AddChild(window);
+  window->Show();
+  EXPECT_EQ(initial_item_count + 1, model_->item_count());
+
+  WmWindow* child_window = WmShell::Get()->NewWindow(ui::wm::WINDOW_TYPE_NORMAL,
+                                                     ui::LAYER_NOT_DRAWN);
+  child_window->SetIntProperty(WmWindowProperty::SHELF_ITEM_TYPE, TYPE_APP);
+  window->AddChild(child_window);
+  child_window->Show();
+  // |child_window| should not result in adding a new entry.
+  EXPECT_EQ(initial_item_count + 1, model_->item_count());
+
+  child_window->Destroy();
+  window->Destroy();
+  EXPECT_EQ(initial_item_count, model_->item_count());
+}
+
 }  // namespace ash