ChromeOS: Keep app list centered when the display rotates by 90 degrees.

ui/app_list/views/app_list_view.h

Index: ui/app_list/views/app_list_view.h
diff --git a/ui/app_list/views/app_list_view.h b/ui/app_list/views/app_list_view.h
index 61c16598ec6a3b4e6a4eb836999f6ca40b034188..5eb79c188d5808002453da207a17c86e431b5c7f 100644
--- a/ui/app_list/views/app_list_view.h
+++ b/ui/app_list/views/app_list_view.h
@@ -17,6 +17,10 @@ namespace base {
 class FilePath;
 }
 
+namespace gfx {
+class Screen;
+}
+
 namespace app_list {
 class ApplicationDragAndDropHost;
 class AppListMainView;
@@ -57,6 +61,15 @@ class APP_LIST_EXPORT AppListView : public views::BubbleDelegateView,
                                    views::BubbleBorder::Arrow arrow,
                                    bool border_accepts_events);
 
+  // Initializes the widget and use the center of the primary display for
+  // positioning.
+  void InitAsBubbleCenteredOnPrimaryDisplay(
+      gfx::NativeView parent,
+      PaginationModel* pagination_model,
+      gfx::Screen* screen_to_keep_centered_on,
+      views::BubbleBorder::Arrow arrow,
+      bool border_accepts_events);
+
   void SetBubbleArrow(views::BubbleBorder::Arrow arrow);
 
   void SetAnchorPoint(const gfx::Point& anchor_point);
@@ -110,6 +123,10 @@ class APP_LIST_EXPORT AppListView : public views::BubbleDelegateView,
                             bool border_accepts_events,
                             const gfx::Vector2d& anchor_offset);
 
+  // Gets the point at the center of the current screen.
+  // |screen_to_keep_centered_on_| must not be NULL.
+  gfx::Point GetCenterPoint();
+
   // Overridden from views::BubbleDelegateView:
   virtual void OnBeforeBubbleWidgetInit(
       views::Widget::InitParams* params,
@@ -148,6 +165,10 @@ class APP_LIST_EXPORT AppListView : public views::BubbleDelegateView,
   ObserverList<AppListViewObserver> observers_;
   scoped_ptr<HideViewAnimationObserver> animation_observer_;
 
+  // If non-NULL, the app list will remain centered on this screen's primary
+  // display.
+  gfx::Screen* screen_to_keep_centered_on_;
+
   DISALLOW_COPY_AND_ASSIGN(AppListView);
 };