Fixing problems with constrained windows (i.e. print preview)

ash/wm/frame_painter.cc

 // 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.
 
 #include "ash/wm/frame_painter.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/window_util.h"
 #include "base/logging.h"  // DCHECK
@@ skipping 591 matching lines @@
     return kActiveWindowOpacity;
   return kInactiveWindowOpacity;
 }
 
 // static
 bool FramePainter::UseSoloWindowHeader() {
   int window_count = 0;
   for (std::set<FramePainter*>::const_iterator it = instances_->begin();
        it != instances_->end();
        ++it) {
-    if (IsVisibleNormalWindow((*it)->window_)) {
+    // The window needs to be a 'normal window'. To exclude constrained windows
+    // the existence of a layout manager gets additionally tested.
+    if (IsVisibleNormalWindow((*it)->window_) &&
+        (!(*it)->window_->GetProperty(aura::client::kConstrainedWindowKey))) {
       window_count++;
       if (window_count > 1)
         return false;
     }
   }
   return window_count == 1;
 }
 
 // static
 void FramePainter::SchedulePaintForSoloWindow() {
   for (std::set<FramePainter*>::const_iterator it = instances_->begin();
        it != instances_->end();
        ++it) {
     FramePainter* painter = *it;
     if (IsVisibleNormalWindow(painter->window_))
       painter->frame_->non_client_view()->SchedulePaint();
   }
 }
 
 }  // namespace ash