Limit constrained windows to the size of the parent view.

chrome/browser/ui/gtk/apps/native_app_window_gtk.cc

Index: chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
diff --git a/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc b/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
index d2c5925b220ba3a5a72d97f2e364cdf5733567c0..12a3d5d8c8d110267bea7f7bcce2576feb393e69 100644
--- a/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
+++ b/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
@@ -384,6 +384,13 @@ gfx::Point NativeAppWindowGtk::GetDialogPosition(const gfx::Size& size) {
                     current_height / 2 - size.height() / 2);
 }
 
+gfx::Size NativeAppWindowGtk::GetMaximumDialogSize() {
+  gint current_width = 0;
+  gint current_height = 0;
+  gtk_window_get_size(window_, &current_width, &current_height);
+  return gfx::Size(current_width, current_height);
+}
+
 void NativeAppWindowGtk::AddObserver(
     web_modal::WebContentsModalDialogHostObserver* observer) {
   observer_list_.AddObserver(observer);