Revert EnableClose() removal and related crash fixes. I don't understand the crashes here, and th...

ui/views/window/non_client_view.h

 // Copyright (c) 2011 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 UI_VIEWS_WINDOW_NON_CLIENT_VIEW_H_
 #define UI_VIEWS_WINDOW_NON_CLIENT_VIEW_H_
 #pragma once
 
 #include "ui/views/view.h"
 #include "ui/views/window/client_view.h"
@@ skipping 35 matching lines @@
   virtual gfx::Rect GetWindowBoundsForClientBounds(
       const gfx::Rect& client_bounds) const = 0;
 
   // This function must ask the ClientView to do a hittest.  We don't do this in
   // the parent NonClientView because that makes it more difficult to calculate
   // hittests for regions that are partially obscured by the ClientView, e.g.
   // HTSYSMENU.
   virtual int NonClientHitTest(const gfx::Point& point) = 0;
   virtual void GetWindowMask(const gfx::Size& size,
                              gfx::Path* window_mask) = 0;
+  virtual void EnableClose(bool enable) = 0;
   virtual void ResetWindowControls() = 0;
   virtual void UpdateWindowIcon() = 0;
 
   // Overridden from View:
   virtual bool HitTest(const gfx::Point& l) const OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
   virtual std::string GetClassName() const OVERRIDE;
 
  protected:
   virtual void OnBoundsChanged(const gfx::Rect& previous_bounds) OVERRIDE;
@@ skipping 101 matching lines @@
   gfx::Rect GetWindowBoundsForClientBounds(const gfx::Rect client_bounds) const;
 
   // Determines the windows HT* code when the mouse cursor is at the
   // specified point, in window coordinates.
   int NonClientHitTest(const gfx::Point& point);
 
   // Returns a mask to be used to clip the top level window for the given
   // size. This is used to create the non-rectangular window shape.
   void GetWindowMask(const gfx::Size& size, gfx::Path* window_mask);
 
+  // Toggles the enable state for the Close button (and the Close menu item in
+  // the system menu).
+  void EnableClose(bool enable);
+
   // Tells the window controls as rendered by the NonClientView to reset
   // themselves to a normal state. This happens in situations where the
   // containing window does not receive a normal sequences of messages that
   // would lead to the controls returning to this normal state naturally, e.g.
   // when the window is maximized, minimized or restored.
   void ResetWindowControls();
 
   // Tells the NonClientView to invalidate the NonClientFrameView's window icon.
   void UpdateWindowIcon();
 
@@ skipping 39 matching lines @@
 
   // The accessible name of this view.
   string16 accessible_name_;
 
   DISALLOW_COPY_AND_ASSIGN(NonClientView);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WINDOW_NON_CLIENT_VIEW_H_