Revert of PlzNavigate: Enforce 'frame-src' CSP on the browser.

chrome/test/data/extensions/api_test/sandboxed_pages_csp/sandboxed.html

Index: chrome/test/data/extensions/api_test/sandboxed_pages_csp/sandboxed.html
diff --git a/chrome/test/data/extensions/api_test/sandboxed_pages_csp/sandboxed.html b/chrome/test/data/extensions/api_test/sandboxed_pages_csp/sandboxed.html
index 3bcce5e24898716bf2d47834c141f5bba4f2eb09..ac13d0bb80ef380059c4aa4d3e6e7f6a3084ceea 100644
--- a/chrome/test/data/extensions/api_test/sandboxed_pages_csp/sandboxed.html
+++ b/chrome/test/data/extensions/api_test/sandboxed_pages_csp/sandboxed.html
@@ -2,19 +2,6 @@
 
 <script>
 // We're not served with the extension default CSP, we can use inline script.
-
-var sendResponse = function(msg) {
-  var mainWindow = window.opener || window.top;
-  mainWindow.postMessage(msg, '*');
-};
-
-var remote_frame_loaded = false;
-window.addEventListener('securitypolicyviolation', function(e) {
-  if (remote_frame_loaded)
-    sendResponse('succeeded');
-  else
-    sendResponse('failed');
-});
 
 var loadFrameExpectResponse = function(iframe, url) {
   var identifier = performance.now();
@@ -38,15 +25,22 @@
 
 var runTestAndRespond = function(localUrl, remoteUrl) {
   var iframe = document.createElement('iframe');
+  var sendResponse = function(msg) {
+    var mainWindow = window.opener || window.top;
+    mainWindow.postMessage(msg, '*');
+  };
 
   // First load local resource in |iframe|, expect the local frame to respond.
   loadFrameExpectResponse(iframe, localUrl).then(function() {
-    // Then load remote resource in |iframe|, expect the navigation to be
-    // blocked by the Content-Security-Policy.
-    // Rely on the SecurityPolicyViolationEvent to detect that the frame has
-    // been blocked.
-    remote_frame_loaded = true;
-    iframe.src = remoteUrl;
+    // Then try to load remote resource on the same iframe element. The remote
+    // resource will fail to load but we'd get an iframe.onload event and the
+    // local frame will still be there. Therefore, expect the local frame to
+    // respond again.
+    return loadFrameExpectResponse(iframe, remoteUrl);
+  }).then(function() {
+    sendResponse('succeeded');
+  }).catch(function(err) {
+    sendResponse('failed');
   });
   document.body.appendChild(iframe);
 };