Added check to prevent extensions from injecting scrips into other extensions

chrome/test/data/extensions/api_test/content_scripts/other_extensions/victim/test.js

Index: chrome/test/data/extensions/api_test/content_scripts/other_extensions/victim/test.js
diff --git a/chrome/test/data/extensions/api_test/content_scripts/other_extensions/victim/test.js b/chrome/test/data/extensions/api_test/content_scripts/other_extensions/victim/test.js
new file mode 100644
index 0000000000000000000000000000000000000000..24756d352286546f1e6769a6220a079534977a65
--- /dev/null
+++ b/chrome/test/data/extensions/api_test/content_scripts/other_extensions/victim/test.js
@@ -0,0 +1,25 @@
+chrome.test.runTests([
+  function content_test() {
+    window.addEventListener('message', function(event) {
+        var msg = event.data;
+        if (msg == 'original') {
+          console.log('VICTIM: No content changed.');
+          chrome.test.succeed();
+        } else {
+          console.log('VICTIM: Detected injected content - ' + msg);
+          chrome.test.fail('Content changed: ' + msg);
+        }
+      },
+      false);
+
+    chrome.test.getConfig(function(config) {
+      chrome.test.log("Creating tab...");
+      var test_url = ("http://a.com:PORT/files/extensions/api_test" +
+          "/content_scripts/other_extensions/iframe_content.html#" +
+          escape(chrome.extension.getURL("test.html")))
+          .replace(/PORT/, config.testServer.port);
+      console.log('Opening frame: ' + test_url);
+      document.getElementById('content_frame').src = test_url;
+    });
+  }
+]);