Fix crash when dragging a half width window to split view from overivew mode

athena/wm/split_view_controller.h

Index: athena/wm/split_view_controller.h
diff --git a/athena/wm/split_view_controller.h b/athena/wm/split_view_controller.h
index 8d8db77aca4bc9ebd03c76a2af3d44f5bc00d1b9..d0e70735e3899f6d892cf028048dddc985ee249e 100644
--- a/athena/wm/split_view_controller.h
+++ b/athena/wm/split_view_controller.h
@@ -11,6 +11,7 @@
 #include "base/memory/weak_ptr.h"
 
 namespace gfx {
+class Rect;
 class Transform;
 }
 
@@ -42,6 +43,13 @@ class ATHENA_EXPORT SplitViewController
   void ReplaceWindow(aura::Window* window,
                      aura::Window* replace_with);
 
+  // Returns the bounds that the left and right windows will have once split
+  // view is active and they are done animating. If |left_window_| and
+  // |right_window_| are still animating this may be different than their
+  // current bounds.
+  gfx::Rect GetLeftTargetBounds();
+  gfx::Rect GetRightTargetBounds();
+
   aura::Window* left_window() { return left_window_; }
   aura::Window* right_window() { return right_window_; }