Fix crash when using title drag on a window opened while split view is active

athena/wm/split_view_controller.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ATHENA_WM_SPLIT_VIEW_CONTROLLER_H_
 #define ATHENA_WM_SPLIT_VIEW_CONTROLLER_H_
 
 #include "athena/athena_export.h"
 #include "athena/wm/bezel_controller.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 20 matching lines @@
   bool IsSplitViewModeActive() const;
 
   // Activates split-view mode with |left| and |right| windows. If |left| and/or
   // |right| is NULL, then the first window in the window-list (which is neither
   // |left| nor |right|) is selected instead.
   void ActivateSplitMode(aura::Window* left, aura::Window* right);
 
   // Resets the internal state to an inactive state. Calling this does not
   // change the window bounds/transforms etc. The caller must take care of
   // making any necessary changes.
   void DeactivateSplitMode();

[oshima, 2014/08/29 21:57:06]

nit: can you update the comment?

 
   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();
@@ skipping 10 matching lines @@
     // there is a horizontal scroll in progress which is dragging the separator
     // between the two windows.
     SCROLLING,
     // Split View mode is active with |left_window_| and |right_window| showing
     // side by side each occupying half the screen. No scroll in progress.
     ACTIVE
   };
 
   void UpdateLayout(bool animate);
 
-  void SetWindowTransform(aura::Window* left_window,
-                          const gfx::Transform& transform,
-                          bool animate);
+  void SetWindowTransforms(const gfx::Transform& left_transform,
+                           const gfx::Transform& right_transform,
+                           bool animate);
 
-  void OnAnimationCompleted(aura::Window* window);
+  void OnAnimationCompleted();

[oshima, 2014/08/29 21:57:06]

can you add comment that this is called once for each transition that involves
animation? (even if we animate two windows, this gets called once, right?)

 
   void UpdateSeparatorPositionFromScrollDelta(float delta);
 
   // BezelController::ScrollDelegate:
   virtual void ScrollBegin(BezelController::Bezel bezel, float delta) OVERRIDE;
   virtual void ScrollEnd() OVERRIDE;
   virtual void ScrollUpdate(float delta) OVERRIDE;
   virtual bool CanScroll() OVERRIDE;
 
   State state_;
@@ skipping 13 matching lines @@
   int separator_position_;
 
   base::WeakPtrFactory<SplitViewController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SplitViewController);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_WM_SPLIT_VIEW_CONTROLLER_H_