Draggable peeking/fullscreen launcher with transparent background.

ui/app_list/views/search_box_view.h

Index: ui/app_list/views/search_box_view.h
diff --git a/ui/app_list/views/search_box_view.h b/ui/app_list/views/search_box_view.h
index 8b5790bc418993e9a1a06de47d20851989d23358..580ea2e73ec9c48bb4fcc6971703722b419c47b9 100644
--- a/ui/app_list/views/search_box_view.h
+++ b/ui/app_list/views/search_box_view.h
@@ -31,6 +31,7 @@ enum SearchBoxFocus {
 };
 
 class AppListModel;
+class AppListView;
 class AppListViewDelegate;
 class SearchBoxModel;
 class SearchBoxViewDelegate;
@@ -47,7 +48,8 @@ class APP_LIST_EXPORT SearchBoxView : public views::View,
                                       public SpeechUIModelObserver {
  public:
   SearchBoxView(SearchBoxViewDelegate* delegate,
-                AppListViewDelegate* view_delegate);
+                AppListViewDelegate* view_delegate,
+                AppListView* app_list_view = nullptr);
   ~SearchBoxView() override;
 
   void ModelChanged();
@@ -118,6 +120,11 @@ class APP_LIST_EXPORT SearchBoxView : public views::View,
   SearchBoxImageButton* speech_button_;  // Owned by views hierarchy.
   views::Textfield* search_box_;  // Owned by views hierarchy.
   views::View* contents_view_;  // Owned by views hierarchy.
+  app_list::AppListView* app_list_view_;  // Owned by views hierarchy.
+
+  // A flag set in the constructor, handled by
+  // features::IsFullscreenAppListEnabled.
+  const bool is_fullscreen_enabled_;

[msw, 2017/06/07 02:31:39]

Move this to a file-local function in cc file's anon namespace, like:
bool IsFullscreenAppListEnabled() {
  // Cache this value to avoid repeated lookup.
  static bool cached_value = features::IsFullscreenAppListEnabled();
  return cached_value;
}

[newcomer, 2017/06/07 17:21:38]

Done.

 
   SearchBoxFocus focused_view_;  // Which element has TAB'd focus.