Tell the RWH about the intial window size for drop down menus.

chrome/browser/renderer_host/render_widget_host_view_gtk.cc

Index: chrome/browser/renderer_host/render_widget_host_view_gtk.cc
diff --git a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
index 939c8f136ab60865f98fe4f28dd65dcdaaefe5e2..b54aba3e9e2749c8fe9e96e301162ee6495189f7 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -358,9 +358,11 @@ void RenderWidgetHostViewGtk::InitAsPopup(
     parent_host_view->Blur();
   }
 
-  gtk_widget_set_size_request(view_.get(),
-                              std::min(pos.width(), kMaxWindowWidth),
+  requested_size_ = gfx::Size(std::min(pos.width(), kMaxWindowWidth),
                               std::min(pos.height(), kMaxWindowHeight));
+  host_->WasResized();
+  gtk_widget_set_size_request(view_.get(), requested_size_.width(),
+                              requested_size_.height());
 
   gtk_window_set_default_size(GTK_WINDOW(popup), -1, -1);
   // Don't allow the window to be resized. This also forces the window to