Highlight relfected XSS vectors in view-source page.

Source/core/html/HTMLViewSourceDocument.h

Index: Source/core/html/HTMLViewSourceDocument.h
diff --git a/Source/core/html/HTMLViewSourceDocument.h b/Source/core/html/HTMLViewSourceDocument.h
index 76595a26d65b07c56bbf39f251c305d00a1f195a..014e92b4770e09e770e81a9f7d6bd40925e5495c 100644
--- a/Source/core/html/HTMLViewSourceDocument.h
+++ b/Source/core/html/HTMLViewSourceDocument.h
@@ -40,7 +40,7 @@ public:
         return adoptRefWillBeRefCountedGarbageCollected(new HTMLViewSourceDocument(initializer, mimeType));
     }
 
-    void addSource(const String&, HTMLToken&);
+    void addSource(const String&, HTMLToken&, bool dangerous);

[Mike West, 2014/05/29 09:29:48]

Nit: Would you mind changing |dangerous| here and |highlight| below into an enum
so that the purpose is clear at the callsite? Perhaps something like
TOKEN_CONSIDERED_XSS and TOKEN_CONSIDERED_SAFE?

 
     virtual void trace(Visitor*) OVERRIDE;
 
@@ -51,15 +51,15 @@ private:
 
     void processDoctypeToken(const String& source, HTMLToken&);
     void processEndOfFileToken(const String& source, HTMLToken&);
-    void processTagToken(const String& source, HTMLToken&);
+    void processTagToken(const String& source, HTMLToken&, bool highlight);

[eseidel, 2014/05/29 14:28:11]

All of these bools are hard to read at callsites:

void processTagToken(source, token, true);  // What does true mean??

Hence, as Mike recommends above, we try to use enums instead.  Even if they're
only used in one place once.

enum ViewSourceHighlight {
   HightlightToken,
   DoNotHighlightToken,
}

or whatever the appropriate choices are.  You can define it inside the class or
not, up to you.

[jww, 2014/05/29 18:35:01]

Just as a further thought that I could see future uses for this where we might
want to highlight different colors for different purposes, and such an enum
would be more flexible for that.

     void processCommentToken(const String& source, HTMLToken&);
-    void processCharacterToken(const String& source, HTMLToken&);
+    void processCharacterToken(const String& source, HTMLToken&, bool highlight);
 
     void createContainingTable();
     PassRefPtr<Element> addSpanWithClassName(const AtomicString&);
     void addLine(const AtomicString& className);
     void finishLine();
-    void addText(const String& text, const AtomicString& className);
+    void addText(const String& text, const AtomicString& className, bool highlight = false);
     int addRange(const String& source, int start, int end, const AtomicString& className, bool isLink = false, bool isAnchor = false, const AtomicString& link = nullAtom);
     PassRefPtr<Element> addLink(const AtomicString& url, bool isAnchor);
     PassRefPtr<Element> addBase(const AtomicString& href);