Resize the render widget host even if the widget is hidden.

chrome/browser/tab_contents/tab_contents_view_gtk.h

Index: chrome/browser/tab_contents/tab_contents_view_gtk.h
diff --git a/chrome/browser/tab_contents/tab_contents_view_gtk.h b/chrome/browser/tab_contents/tab_contents_view_gtk.h
index 8e3fcf605f303dbfcd88386673e09cb1be3e75ee..12bc936284a404a6504ab35b4476faa5e19acb04 100644
--- a/chrome/browser/tab_contents/tab_contents_view_gtk.h
+++ b/chrome/browser/tab_contents/tab_contents_view_gtk.h
@@ -139,6 +139,10 @@ class TabContentsViewGtk : public TabContentsView,
   // Object responsible for handling drags from the page for us.
   scoped_ptr<TabContentsDragSource> drag_source_;
 
+  // The size we want the tab contents view to be.  We keep this in a separate
+  // variable because resizing in GTK+ is async.
+  gfx::Size requested_size_;
+
   DISALLOW_COPY_AND_ASSIGN(TabContentsViewGtk);
 };