Ensure that an activity is activated when overview mode is exited

athena/wm/window_overview_mode.h

Index: athena/wm/window_overview_mode.h
diff --git a/athena/wm/window_overview_mode.h b/athena/wm/window_overview_mode.h
index 6597fea433d8c170164bc1fce6193579c6e83955..abce22158252f20dde79c9dd8b828a44c331efa4 100644
--- a/athena/wm/window_overview_mode.h
+++ b/athena/wm/window_overview_mode.h
@@ -14,15 +14,20 @@ class WindowListProvider;
 
 class WindowOverviewModeDelegate {
  public:
-  virtual ~WindowOverviewModeDelegate() {}
+  enum SplitType {
+    SPLIT_NONE,
+    SPLIT_LEFT,
+    SPLIT_RIGHT
+  };
 
-  virtual void OnSelectWindow(aura::Window* window) = 0;
+  virtual ~WindowOverviewModeDelegate() {}
 
-  // Gets into split-view mode with |left| on the left-side of the screen, and
-  // |right| on the right-side. If |left| or |right| is NULL, then the delegate
-  // selects the best option in its place.
-  virtual void OnSplitViewMode(aura::Window* left,
-                               aura::Window* right) = 0;
+  // Called when a window is selected in overview mode. |window| is the window
+  // to be activated. |window| is NULL if there are no windows in overview mode.
+  // |split_type| indicates whether the window should be part
+  // of split view and what position it should have in split view. The method
+  // should update |window|'s bounds, opacity and visibility.
+  virtual void OnSelectWindow(aura::Window* window, SplitType split_type) = 0;
 };
 
 class WindowOverviewMode {
@@ -34,6 +39,9 @@ class WindowOverviewMode {
       const WindowListProvider* window_list_provider,
       SplitViewController* split_view_controller,
       WindowOverviewModeDelegate* delegate);
+
+  // Selects the default window based on overview mode's current state.
+  virtual void SelectDefaultWindow() = 0;
 };
 
 }  // namespace athena