Remove deprecated StringBuffer.add, addAll and addCharCode.

utils/apidoc/mdn/extract.dart

 import 'dart:html';
 import 'dart:json' as json;
 
 // Workaround for HTML lib missing feature.
 Range newRange() {
   return document.createRange();
 }
 
 // Temporary range object to optimize performance computing client rects
 // from text nodes.
@@ skipping 593 matching lines @@
   // Strip tags we don't want
   for (Element e in fragment.queryAll("script, object, style")) {
     e.remove();
   }
 
   // Extract idl
   final idl = new StringBuffer();
   if (prop != null && prop.length > 0) {
     // Only expect properties to have HTML.
     for(Element e in fragment.queryAll(IDL_SELECTOR)) {
-      idl.add(e.outerHTML);
+      idl.write(e.outerHTML);
       e.remove();
     }
     // TODO(jacobr) this is a very basic regex to see if text looks like IDL
     RegExp likelyIdl = new RegExp(" $prop\\w*\\(");
 
     for (Element e in fragment.queryAll("pre")) {
       // Check if it looks like idl...
       String txt = e.text.trim();
       if (likelyIdl.hasMatch(txt) && txt.contains("\n") && txt.contains(")")) {
-        idl.add(e.outerHTML);
+        idl.write(e.outerHTML);
         e.remove();
       }
     }
   }
   return new SectionParseResult(genCleanHtml(fragment), url, idl.toString());
 }
 
 /**
  * Find the best child element of [root] that appears to be an API definition
  * for [prop].  [allText] is a list of all text nodes under root computed by
@@ skipping 631 matching lines @@
   }
   if (exampleHtml.length > 0) {
     dbEntry['examples'] = exampleHtml;
   }
 
   // Extract the class summary.
   // Basically everything left over after the #Summary or #Description tag is
   // safe to include in the summary.
   StringBuffer summary = new StringBuffer();
   for (Element e in root.queryAll("#Summary, #Description")) {
-    summary.add(filteredHtml(root, e, null, removeHeaders).html);
+    summary.write(filteredHtml(root, e, null, removeHeaders).html);
   }
 
   if (summary.length == 0) {
     // Remove the "Gecko DOM Reference text"
     Element ref = root.query(".lang.lang-en");
     if (ref != null) {
       ref = ref.parent;
       String refText = ref.text.trim();
       if (refText == "Gecko DOM Reference" ||
           refText == "« Gecko DOM Reference") {
         ref.remove();
       }
     }
     // Risky... this might add stuff we shouldn't.
-    summary.add(filteredHtml(root, root, null, removeHeaders).html);
+    summary.write(filteredHtml(root, root, null, removeHeaders).html);
   }
 
   if (summary.length > 0) {
     dbEntry['summary'] = summary.toString();
   }
 
   // Inject CSS to aid debugging in the browser.
   // We could avoid doing this if we know we are not running in a browser..
   document.head.nodes.add(new Element.html(DEBUG_CSS));
 
   onEnd();
 }
 
 void main() {
   window.on.load.add(documentLoaded);
 }
 
 void documentLoaded(event) {
   // Load the database of expected methods and properties with an HttpRequest.
   new HttpRequest.get('${window.location}.json', (req) {
     data = json.parse(req.responseText);
     dbEntry = {'members': [], 'srcUrl': pageUrl};
     run();
   });
 }