GTK: Compute infobubble rects correctly.

chrome/common/gtk_util.cc

Index: chrome/common/gtk_util.cc
diff --git a/chrome/common/gtk_util.cc b/chrome/common/gtk_util.cc
index 842b99ab19e8c02487a6d8675b0985d05ffe4793..fac62f491297cacc8dcf42a2195984ec37cb786b 100644
--- a/chrome/common/gtk_util.cc
+++ b/chrome/common/gtk_util.cc
@@ -568,4 +568,13 @@ void StackPopupWindow(GtkWidget* popup, GtkWidget* toplevel) {
   }
 }
 
+gfx::Rect GetWidgetRectRelativeToToplevel(GtkWidget* widget) {
+  gint x = 0, y = 0;
+  DCHECK(gtk_widget_translate_coordinates(widget,
+                                          gtk_widget_get_toplevel(widget),
+                                          0, 0,
+                                          &x, &y));
+  return gfx::Rect(x, y, widget->allocation.width, widget->allocation.height);
+}
+
 }  // namespace gtk_util