[Test] Added a test for activeTab URL filtering

chrome/test/data/extensions/api_test/active_tab/background.js

Index: chrome/test/data/extensions/api_test/active_tab/background.js
diff --git a/chrome/test/data/extensions/api_test/active_tab/background.js b/chrome/test/data/extensions/api_test/active_tab/background.js
index 7ccd11832dac9ca9f863f5a5fff8fddaaabf4e20..81186903e2566b6c21c0820c9ef29c9a38e64eb9 100644
--- a/chrome/test/data/extensions/api_test/active_tab/background.js
+++ b/chrome/test/data/extensions/api_test/active_tab/background.js
@@ -42,7 +42,18 @@ var injectIframe =
     'iframe.src = "' + iframeUrl + '";\n' +
     'document.body.appendChild(iframe);\n';
 
+var runCount = 0;
+
 chrome.browserAction.onClicked.addListener(function(tab) {
+  runCount++;
+  if (runCount == 1) {

[Devlin, 2017/05/23 20:49:21]

add some comments explaining the ordering here.

[Ivan Šandrk, 2017/05/24 16:36:51]

Done.

+    assertTrue(tab.url == undefined);

[Devlin, 2017/05/23 20:49:21]

maybe just: assertFalse(!!tab.url);

[Ivan Šandrk, 2017/05/24 16:36:51]

Done.

+    return chrome.test.succeed();

[Devlin, 2017/05/23 20:49:21]

chrome.test.succeed() doesn't return anything, so prefer:
chrome.test.succeed();
return;

[Ivan Šandrk, 2017/05/24 16:36:51]

Done.

+  } else if (runCount == 3) {
+    chrome.test.sendMessage(tab.url);
+    return chrome.test.succeed();
+  }
+
   iframeDone = chrome.test.callbackAdded();
   cachedUrl = tab.url;
   chrome.tabs.executeScript({ code: injectIframe }, callbackPass());