[mus+ash] Fixes minimum browser window size (store / retrieve kPreferredSize property)

chrome/browser/ui/views/frame/browser_non_client_frame_view_mus.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 "chrome/browser/ui/views/frame/browser_non_client_frame_view_mus.h"
 
 #include <algorithm>
 
 #include "chrome/browser/profiles/profiles_state.h"
 #include "chrome/browser/themes/theme_properties.h"
@@ skipping 208 matching lines @@
       // clicks in the frame decoration.
       static_cast<aura::WindowTreeHostMus*>(
           reveal_widget->GetNativeWindow()->GetHost())
           ->SetClientArea(client_area_insets, additional_client_area);
     }
   } else {
     window_tree_host_mus->SetClientArea(gfx::Insets(), additional_client_area);
   }
 }
 
+void BrowserNonClientFrameViewMus::UpdateMinimumSize() {
+  gfx::Size min_size = GetMinimumSize();
+  aura::Window* frame_window = frame()->GetNativeWindow();
+  const gfx::Size* previous_min_size =
+      frame_window->GetProperty(aura::client::kMinimumSize);
+  if (!previous_min_size || *previous_min_size != min_size) {
+    frame_window->SetProperty(aura::client::kMinimumSize,
+                              new gfx::Size(min_size));
+  }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // views::NonClientFrameView:
 
 gfx::Rect BrowserNonClientFrameViewMus::GetBoundsForClientView() const {
   // The ClientView must be flush with the top edge of the widget so that the
   // web contents can take up the entire screen in immersive fullscreen (with
   // or without the top-of-window views revealed). When in immersive fullscreen
   // and the top-of-window views are revealed, the TopContainerView paints the
   // window header by redirecting paints from its background to
   // BrowserNonClientFrameViewMus.
@@ skipping 277 matching lines @@
   // TODO: move ash_layout_constants to ash/public/cpp.
   const bool restored = !frame()->IsMaximized() && !frame()->IsFullscreen();
   return GetAshLayoutSize(restored
                               ? AshLayoutSize::BROWSER_RESTORED_CAPTION_BUTTON
                               : AshLayoutSize::BROWSER_MAXIMIZED_CAPTION_BUTTON)
       .height();
 #else
   return views::WindowManagerFrameValues::instance().normal_insets.top();
 #endif
 }