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

Source/core/dom/StyleElement.h

Index: Source/core/dom/StyleElement.h
diff --git a/Source/core/dom/StyleElement.h b/Source/core/dom/StyleElement.h
index ef2d28e3d4deea32455cf73f24e2066c09c7768d..60c49e78de901e76f4beb1005bca423e0a83885a 100644
--- a/Source/core/dom/StyleElement.h
+++ b/Source/core/dom/StyleElement.h
@@ -37,6 +37,11 @@ public:
     DECLARE_VIRTUAL_TRACE();
 
 protected:
+    enum ProcessingResult {
+        ProcessingSuccessful,
+        ProcessingFatalError
+    };
+
     virtual const AtomicString& type() const = 0;
     virtual const AtomicString& media() const = 0;
 
@@ -48,16 +53,16 @@ protected:
 
     void insertedInto(Element*, ContainerNode* insertionPoint);
     void removedFrom(Element*, ContainerNode* insertionPoint);
-    void processStyleSheet(Document&, Element*);
     void clearDocumentData(Document&, Element*);
-    void childrenChanged(Element*);
-    void finishParsingChildren(Element*);
+    ProcessingResult processStyleSheet(Document&, Element*);
+    ProcessingResult childrenChanged(Element*);
+    ProcessingResult finishParsingChildren(Element*);
 
     RefPtrWillBeMember<CSSStyleSheet> m_sheet;
 
 private:
-    void createSheet(Element*, const String& text = String());
-    void process(Element*);
+    ProcessingResult createSheet(Element*, const String& text = String());
+    ProcessingResult process(Element*);
     void clearSheet(Element* ownerElement = 0);
 
     bool m_createdByParser : 1;