Don't use drag to corner resizing for unresizable windows

ash/wm/window_util.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_WINDOW_UTIL_H_
 #define ASH_WM_WINDOW_UTIL_H_
 
 #include "ash/ash_export.h"
 #include "base/compiler_specific.h"
 #include "ui/base/ui_base_types.h"
@@ skipping 30 matching lines @@
 // If you're looking for a function to get the activatable "top level" window,
 // this is probably what you're looking for.
 ASH_EXPORT aura::Window* GetActivatableWindow(aura::Window* window);
 
 // Returns true if the active window or one its ancestors is fullscreen.
 ASH_EXPORT bool IsActiveWindowFullscreen();
 
 // Returns true if |window| can be maximized.
 ASH_EXPORT bool CanMaximizeWindow(const aura::Window* window);
 
+// Returns true if |window| can be resized.
+ASH_EXPORT bool CanResizeWindow(const aura::Window* window);
+
 // Returns true if |window| is normal or default.
 ASH_EXPORT bool IsWindowNormal(const aura::Window* window);
 
 // Returns true if |state| is normal or default.
 ASH_EXPORT bool IsWindowStateNormal(const ui::WindowShowState state);
 
 // Returns true if |window| is in the maximized state.
 ASH_EXPORT bool IsWindowMaximized(const aura::Window* window);
 
 // Returns true if |window| is minimized.
@@ skipping 57 matching lines @@
 
 // Move the given bounds inside the given work area, including a safety margin.
 ASH_EXPORT void AdjustBoundsToEnsureWindowVisibility(
     gfx::Rect* bounds,
     const gfx::Rect& work_area);
 
 }  // namespace wm
 }  // namespace ash
 
 #endif  // ASH_WM_WINDOW_UTIL_H_