exo: Prevent maximize/minimize of shell surface in system modal container.

components/exo/shell_surface.cc

 // Copyright 2015 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.
 
 #include "components/exo/shell_surface.h"
 
 #include "ash/aura/wm_window_aura.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/wm/window_resizer.h"
 #include "ash/common/wm/window_state.h"
@@ skipping 634 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // views::WidgetDelegate overrides:
 
 bool ShellSurface::CanResize() const {
   return initial_bounds_.IsEmpty();
 }
 
 bool ShellSurface::CanMaximize() const {
-  return true;
+  // Shell surfaces in system modal container cannot be maximized.
+  return container_ != ash::kShellWindowId_SystemModalContainer;
 }
 
 bool ShellSurface::CanMinimize() const {
-  return true;
+  // Shell surfaces in system modal container cannot be minimized.
+  return container_ != ash::kShellWindowId_SystemModalContainer;
 }
 
 base::string16 ShellSurface::GetWindowTitle() const {
   return title_;
 }
 
 void ShellSurface::WindowClosing() {
   if (resizer_)
     EndDrag(true /* revert */);
   SetEnabled(false);
@@ skipping 570 matching lines @@
       shadow_overlay_->layer()->Add(shadow->layer());
       window->AddChild(shadow_overlay_);
       shadow_overlay_->Show();
     }
     shadow_overlay_->SetBounds(shadow_bounds);
     shadow->SetContentBounds(gfx::Rect(shadow_bounds.size()));
   }
 }
 
 }  // namespace exo