[mus+ash] Removes WmWindow from RootWindowcontroller implementation

ash/wm/window_util.h

Index: ash/wm/window_util.h
diff --git a/ash/wm/window_util.h b/ash/wm/window_util.h
index 1697eebc694595a1acb9002bec14566a40ab1245..d3fcf3d5ba078d0fca0b54c1c9f8e39a3a0b479f 100644
--- a/ash/wm/window_util.h
+++ b/ash/wm/window_util.h
@@ -77,6 +77,11 @@ ASH_EXPORT void SetSnapsChildrenToPhysicalPixelBoundary(
 ASH_EXPORT int GetNonClientComponent(aura::Window* window,
                                      const gfx::Point& location);
 
+// When set, the child windows should get a slightly larger hit region to make
+// resizing easier.
+ASH_EXPORT void SetChildrenUseExtendedHitRegionForWindow(aura::Window* window);
+ASH_EXPORT bool ShouldUseExtendedHitRegionForWindow(const aura::Window* window);
+
 // Requests the |window| to close and destroy itself. This is intended to
 // forward to an associated widget.
 ASH_EXPORT void CloseWidgetForWindow(aura::Window* window);