Adding proper dragging behavior for L/R maximized windows.

ash/wm/frame_painter.h

Index: ash/wm/frame_painter.h
diff --git a/ash/wm/frame_painter.h b/ash/wm/frame_painter.h
index 57045e3c4de21967b4a64ad3394183720ddf1639..cd725d475d60ea530a2ce01274ccab96cf361d11 100644
--- a/ash/wm/frame_painter.h
+++ b/ash/wm/frame_painter.h
@@ -141,6 +141,9 @@ class ASH_EXPORT FramePainter : public aura::WindowObserver,
                        int theme_frame_id,
                        const gfx::ImageSkia* theme_frame_overlay);
 
+  // Adjust frame operations for left / right maximized modes.
+  int AdjustFrameHitCodeForMaximizedModes(int hit_code);
+
   // Returns true if there is exactly one visible, normal-type window using
   // a header painted by this class, in which case we should paint a transparent
   // window header.