ServiceWorker: Remove iframes explicitly after a test is finished

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/test-helpers.js

Index: third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/test-helpers.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/test-helpers.js b/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/test-helpers.js
index 65215669d63e267a851f047b4f28bd4b1e3cc650..97138d20e14e7b3b3f08b15fd3fba63b4a667c0e 100644
--- a/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/test-helpers.js
+++ b/third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/test-helpers.js
@@ -44,14 +44,19 @@ function unreached_rejection(test, prefix) {
 }
 
 // Adds an iframe to the document and returns a promise that resolves to the
-// iframe when it finishes loading. The caller is responsible for removing the
-// iframe later if needed.
-function with_iframe(url) {
+// iframe when it finishes loading. When |reclaim_after_completion| is set to
+// |IFRAME_RECLAMATION.FALSE|, the caller is responsible for removing the iframe
+// later. Otherwise, the frame will be removed after all tests are finished.
+var IFRAME_RECLAMATION = Object.freeze({TRUE: true, FALSE: false});

[nhiroki, 2016/04/07 05:37:18]

How about using 'const' keyword instead?

  const DONT_RECLAIM_IFRAME = true;

And, maybe we can reduce the condition like this:

  function with_iframe(url, dont_reclaim_iframe) {
      // ...
      if (DONT_RECLAIM_IFRAME === dont_reclaim_iframe)
        return;
      add_completion_callback(function() { frame.remove(); });
  }

[falken, 2016/04/07 05:47:26]

Sorry for more drive-bys, just thought of this. Passing an optional options
object like:
{auto_remove: false}
seems a bit more common in the JS world?

[shimazu (google), 2016/04/07 06:53:55]

I think so, and fixed it.

+function with_iframe(url, reclaim_after_completion) {
   return new Promise(function(resolve) {
       var frame = document.createElement('iframe');
       frame.src = url;
       frame.onload = function() { resolve(frame); };
       document.body.appendChild(frame);
+      if (typeof reclaim_after_completion === 'undefined' ||
+          reclaim_after_completion === IFRAME_RECLAMATION.TRUE)
+        add_completion_callback(function() { frame.remove(); });
     });
 }