Implement onCompleted event for the webNavigation API

chrome/test/data/extensions/api_test/webnavigation/navigation2/test.html

 <script>
 var expectedEventData;
 var capturedEventData;
 var nextFrameId;
 var frameIds;
 
 function expect(data) {
   expectedEventData = data;
   capturedEventData = [];
   nextFrameId = 1;
@@ skipping 29 matching lines @@
 
 chrome.experimental.webNavigation.onCommitted.addListener(function(details) {
   captureEvent("onCommitted", details);
 });
 
 chrome.experimental.webNavigation.onDOMContentLoaded.addListener(
   function(details) {
     captureEvent("onDOMContentLoaded", details);
 });
 
+chrome.experimental.webNavigation.onCompleted.addListener(
+  function(details) {
+    captureEvent("onCompleted", details);
+});
+
 chrome.experimental.webNavigation.onErrorOccurred.addListener(
   function(details) {
     captureEvent("onErrorOccurred", details);
 });
 
 var getURL = chrome.extension.getURL;
 chrome.tabs.getSelected(null, function(tab) {
   var tabId = tab.id;
 
   chrome.test.runTests([
@@ skipping 40 matching lines @@
         [ "onDOMContentLoaded",
           { frameId: 0,
             tabId: tabId,
             timeStamp: 0,
             url: getURL('iframeFail/d.html') }],
         [ "onErrorOccurred",
           { error: "net::ERR_FILE_NOT_FOUND",
             frameId: 1,
             tabId: tabId,
             timeStamp: 0,
-            url: getURL('iframeFail/c.html') }]]);
+            url: getURL('iframeFail/c.html') }],
+        [ "onCompleted",
+          { frameId: 0,
+            tabId: tabId,
+            timeStamp: 0,
+            url: getURL('iframeFail/d.html') }]]);
       chrome.tabs.update(tabId, { url: getURL('iframeFail/d.html') });
     },
 
     /* An iframe navigates to a non-existant page. */
     function nonExistantIframeNavigation() {
       expect([
         [ "onBeforeNavigate",
           { frameId: 0,
             requestId: 0,
             tabId: tabId,
@@ skipping 22 matching lines @@
             tabId: tabId,
             timeStamp: 0,
             transitionQualifiers: "",
             transitionType: "auto_subframe",
             url: getURL('iframeFail/b.html') }],
         [ "onDOMContentLoaded",
           { frameId: 1,
             tabId: tabId,
             timeStamp: 0,
             url: getURL('iframeFail/b.html') }],
+        [ "onCompleted",
+          { frameId: 1,
+            tabId: tabId,
+            timeStamp: 0,
+            url: getURL('iframeFail/b.html') }],
+        [ "onCompleted",
+          { frameId: 0,
+            tabId: tabId,
+            timeStamp: 0,
+            url: getURL('iframeFail/a.html') }],
         [ "onBeforeNavigate",
           { frameId: 1,
             requestId: 0,
             tabId: tabId,
             timeStamp: 0,
             url: getURL('iframeFail/c.html') }],
         [ "onErrorOccurred",
           { error: "net::ERR_FILE_NOT_FOUND",
             frameId: 1,
             tabId: tabId,
             timeStamp: 0,
             url: getURL('iframeFail/c.html') }]]);
       chrome.tabs.update(tabId, { url: getURL('iframeFail/a.html') });
     },
   ]);
 });
 </script>