Attempt 2: Allows tab dragging when maximized on aura. To fix it I made it so

ash/wm/workspace/workspace_window_resizer.h

 // Copyright (c) 2012 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 ASH_WM_WORKSPACE_WINDOW_RESIZER_H_
 #define ASH_WM_WORKSPACE_WINDOW_RESIZER_H_
 #pragma once
 
 #include "ash/wm/window_resizer.h"
 #include "base/compiler_specific.h"
@@ skipping 25 matching lines @@
   static void ClearHeightBeforeObscured(aura::Window* window);
   static int GetHeightBeforeObscured(aura::Window* window);
 
   // Adjusts the bounds to enforce that windows are vertically contained in the
   // work area.
   void AdjustBounds(gfx::Rect* bounds) const;
 
   // Returns true if the window touches the bottom of the work area.
   bool WindowTouchesBottomOfScreen() const;
 
+  // True if the window size (height) should be constrained.
+  const bool constrain_size_;
+
   DISALLOW_COPY_AND_ASSIGN(WorkspaceWindowResizer);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_WORKSPACE_WINDOW_RESIZER_H_