Update references to the extension messaging APIs to point to the "runtime"

tools/page_cycler/webpagereplay/extension/start.js

Index: tools/page_cycler/webpagereplay/extension/start.js
diff --git a/tools/page_cycler/webpagereplay/extension/start.js b/tools/page_cycler/webpagereplay/extension/start.js
index 4808996ce8f0a5f32f502c55a8d83d6b0396fea0..ef4ce30120db656f12bdc070b91797fbe11f7c66 100644
--- a/tools/page_cycler/webpagereplay/extension/start.js
+++ b/tools/page_cycler/webpagereplay/extension/start.js
@@ -71,7 +71,7 @@ function TryStart() {
     var reportDir = dirname(dirname(window.location.pathname)) + "/common";
     config["reportUrl"] = "file://" + reportDir + "/report.html";
     config["isRecordMode"] = isRecordMode;
-    var port = chrome.extension.connect();
+    var port = chrome.runtime.connect();
     port.postMessage({message: "start", benchmark: config});
     console.log("sending start message: page count, " +
                 config["pageSets"].length);