Created min size for print preview dialog and modified to allow the

chrome/browser/ui/views/native_web_contents_modal_dialog_manager_views.cc

 // Copyright 2016 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 "chrome/browser/ui/views/native_web_contents_modal_dialog_manager_views.h"
 
 #include <memory>
 
 #include "chrome/browser/platform_util.h"
 #include "components/constrained_window/constrained_window_views.h"
@@ skipping 59 matching lines @@
   gfx::NativeView parent = platform_util::GetParent(widget->GetNativeView());
   wm::SetChildWindowVisibilityChangesAnimated(parent);
   // No animations should get performed on the window since that will re-order
   // the window stack which will then cause many problems.
   if (parent && parent->parent()) {
     parent->parent()->SetProperty(aura::client::kAnimationsDisabledKey, true);
   }
 
   wm::SetModalParent(widget->GetNativeWindow(),
                      native_delegate_->GetWebContents()->GetNativeView());
+
+  if (native_delegate_->IsNonClipped(dialog())) {

[Mike Wittman, 2016/08/12 22:51:34]

We should only enable this code on the platforms where
wm::kHasIndependentBoundsKey is supported. Setting the property in cases where
it has no effect will be confusing to anyone looking at the native window
properties while debugging.

[rbpotter, 2016/08/15 18:03:45]

Done.

+    widget->SetNativeWindowProperty(wm::kHasIndependentBoundsKey,
+                                    new bool(true));

[Mike Wittman, 2016/08/12 22:51:34]

For ease of use and to avoid leaking memory, I would encode the truth value in
the property value itself: reinterpret_cast<void*>(true).

Then users can directly check the property value:
if (widget->GetNativeWindowProperty(wm::kHasIndependentBoundsKey)) {
  // ...
}

[rbpotter, 2016/08/15 18:03:45]

Done.

+  }
 #endif
 }
 
 // SingleWebContentsDialogManager:
 
 void NativeWebContentsModalDialogManagerViews::Show() {
   // The host destroying means the dialogs will be destroyed in short order.
   // Avoid showing dialogs at this point as the necessary native window
   // services may not be present.
   if (host_destroying_)
@@ skipping 121 matching lines @@
   widget->RemoveObserver(this);
   observed_widgets_.erase(widget);
 
 #if defined(USE_AURA)
   shown_widgets_.erase(widget);
 #endif
 
   // Will cause this object to be deleted.
   native_delegate_->WillClose(widget->GetNativeWindow());
 }