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

ash/frame/custom_frame_view_ash.cc

Index: ash/frame/custom_frame_view_ash.cc
diff --git a/ash/frame/custom_frame_view_ash.cc b/ash/frame/custom_frame_view_ash.cc
index 7fd4fed38d908397aafc28c43f055e33474aa468..7136ec85191fa1c90ae28781890768f026e7a86c 100644
--- a/ash/frame/custom_frame_view_ash.cc
+++ b/ash/frame/custom_frame_view_ash.cc
@@ -376,9 +376,19 @@ gfx::Size CustomFrameViewAsh::GetMinimumSize() const {
     return gfx::Size();
 
   gfx::Size min_client_view_size(frame_->client_view()->GetMinimumSize());
-  return gfx::Size(
+  gfx::Size min_size(
       std::max(header_view_->GetMinimumWidth(), min_client_view_size.width()),
       NonClientTopBorderHeight() + min_client_view_size.height());
+
+  aura::Window* frame_window = frame_->GetNativeWindow();
+  const gfx::Size* min_window_size =
+      frame_window->GetProperty(aura::client::kMinimumSize);
+  if (min_window_size) {
+    min_size =
+        gfx::Size(std::max(min_size.width(), min_window_size->width()),
+                  std::max(min_size.height(), min_window_size->height()));
+  }
+  return min_size;
 }
 
 gfx::Size CustomFrameViewAsh::GetMaximumSize() const {