Fire error events for a variety of script and style failures.

Source/core/dom/Node.h

Index: Source/core/dom/Node.h
diff --git a/Source/core/dom/Node.h b/Source/core/dom/Node.h
index 8983c5a5ae865b2a6cfff8de1e24eac2821974a9..42e99e611d620c4867cf79f247d262e39950c7d9 100644
--- a/Source/core/dom/Node.h
+++ b/Source/core/dom/Node.h
@@ -340,7 +340,11 @@ public:
 
     // For <link> and <style> elements.
     virtual bool sheetLoaded() { return true; }
-    virtual void notifyLoadedSheetAndAllCriticalSubresources(bool /* error loading subresource */) { }
+    enum LoadedSheetErrorStatus {
+        NoErrorLoadingSubresource,
+        ErrorOccurredLoadingSubresource
+    };
+    virtual void notifyLoadedSheetAndAllCriticalSubresources(LoadedSheetErrorStatus) { }
     virtual void startLoadingDynamicSheet() { ASSERT_NOT_REACHED(); }
 
     bool hasName() const { ASSERT(!isTextNode()); return getFlag(HasNameOrIsEditingTextFlag); }