Convert the RSS extension to event pages to avoid a dedicated background process.

chrome/test/data/extensions/subscribe_page_action/feed_finder.js

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // First check to see if this document is a feed. If so, it will redirect.
 // Otherwise, check if it has embedded feed links, such as:
 // (<link rel="alternate" type="application/rss+xml" etc). If so, show the
 // page action icon.
 
 debugMsg(logLevels.info, "Running feed finder script");
@@ skipping 15 matching lines @@
   var feeds = [];
   var item;
   var count = 0;
   while (item = result.iterateNext()) {
     feeds.push({"href": item.href, "title": item.title});
     ++count;
   }
 
   if (count > 0) {
     // Notify the extension needs to show the RSS page action icon.
-    chrome.extension.sendRequest({msg: "feedIcon", feeds: feeds});
+    chrome.extension.sendMessage({msg: "feedIcon", feeds: feeds});
   }
 }
 
 // Check to see if the current document is a feed delivered as plain text,
 // which Chrome does for some mime types, or a feed wrapped in an html.
 function isFeedDocument() {
   var body = document.body;
 
   debugMsg(logLevels.info, "Checking if document is feed");
 
   var soleTagInBody = "";
   if (body && body.childElementCount == 1) {
     soleTagInBody = body.children[0].tagName;
     debugMsg(logLevels.info, "The sole tag in the body is: " + soleTagInBody);
   }
 
   // Some feeds show up as feed tags within the BODY tag, for example some
   // ComputerWorld feeds. We cannot check for this at document_start since
   // the body tag hasn't been defined at that time (contains only HTML element
   // with no children).
   if (soleTagInBody == "RSS" || soleTagInBody == "FEED" ||
       soleTagInBody == "RDF") {
     debugMsg(logLevels.info, "Found feed: Tag is: " + soleTagInBody);
-    chrome.extension.sendRequest({msg: "feedDocument", href: location.href});
+    chrome.extension.sendMessage({msg: "feedDocument", href: location.href});
     return true;
   }
 
   // Chrome renders some content types like application/rss+xml and
   // application/atom+xml as text/plain, resulting in a body tag with one
   // PRE child containing the XML. So, we attempt to parse it as XML and look
   // for RSS tags within.
   if (soleTagInBody == "PRE") {
     debugMsg(logLevels.info, "Found feed: Wrapped in PRE");
     var domParser = new DOMParser();
     var doc = domParser.parseFromString(body.textContent, "text/xml");
 
     if (currentLogLevel >= logLevels.error) {
       var error = doc.getElementsByTagName("parsererror");
       if (error.length)
         debugMsg(logLevels.error, 'error: ' + doc.childNodes[0].outerHTML);
     }
 
     // |doc| now contains the parsed document within the PRE tag.
     if (containsFeed(doc)) {
       // Let the extension know that we should show the subscribe page.
-      chrome.extension.sendRequest({msg: "feedDocument", href: location.href});
+      chrome.extension.sendMessage({msg: "feedDocument", href: location.href});
       return true;
     }
   }
 
   debugMsg(logLevels.info, "Exiting: feed is not a feed document");
 
   return false;
 }