Don't fail the style assert in Element::rendererIsFocusable if the document is active.

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index 7f7a9a06ab6a6cc3ac920dbf1a2572a23eb3d8a8..04efa32033cf007e153f2f7d5487304d5665421c 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -237,7 +237,9 @@ bool Element::rendererIsFocusable() const
         // We can't just use needsStyleRecalc() because if the node is in a
         // display:none tree it might say it needs style recalc but the whole
         // document is actually up to date.
-        ASSERT(!document().childNeedsStyleRecalc());
+        // In addition, style cannot be cleared out for non-active documents,
+        // so in that case the childNeedsStyleRecalc check is invalid.
+        ASSERT(!document().isActive() || !document().childNeedsStyleRecalc());
     }
 
     // FIXME: Even if we are not visible, we might have a child that is visible.