Asynchronously resolve getAvailability callbacks.

content/browser/presentation/presentation_browsertest.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/public/test/browser_test.h"
+#include "content/public/test/content_browser_test.h"
+#include "content/public/test/content_browser_test_utils.cc"
+#include "content/shell/browser/shell.h"
+
+namespace content {
+
+using PresentationBrowserTest = ContentBrowserTest;
+
+// Regression test that verifies that calling getAvailability() twice on the
+// same PresentationRequest does not return an undefined object.
+IN_PROC_BROWSER_TEST_F(PresentationBrowserTest, AvailabilityNotUndefined) {
+  GURL test_url = GetTestUrl("", "hello.html");
+
+  TestNavigationObserver navigation_observer(shell()->web_contents(), 1);
+  shell()->LoadURL(test_url);
+
+  navigation_observer.Wait();
+
+  ExecuteScriptAndGetValue(shell()->web_contents()->GetMainFrame(),
+                           "var r = new PresentationRequest('foo.html')");

[mark a. foltz, 2016/10/05 16:04:01]

nit: s/var/const/ here and below (assuming it doesn't change the meaning of the
test)

[mlamouri (slow - plz ping), 2016/10/05 16:43:13]

Sure. 

+
+  ExecuteScriptAndGetValue(shell()->web_contents()->GetMainFrame(),
+                           "var p1 = r.getAvailability();");
+
+  ExecuteScriptAndGetValue(shell()->web_contents()->GetMainFrame(),
+                           "var p2 = r.getAvailability()");
+
+  bool is_p1_undefined = false;
+  ExecuteScriptAndGetValue(shell()->web_contents()->GetMainFrame(),
+                           "p1 === undefined")->GetAsBoolean(&is_p1_undefined);

[mark a. foltz, 2016/10/05 16:04:01]

There's a spec change coming that getAvailability() will return the same object
in the same script context.
Can you add a TODO(crbug.com/653131) here to add an assertion that p1 === p2?

[mlamouri (slow - plz ping), 2016/10/05 16:43:13]

Done. Though, I would expect us to test this in Blink.

+
+  bool is_p2_undefined = false;
+  ExecuteScriptAndGetValue(shell()->web_contents()->GetMainFrame(),
+                           "p2 === undefined")->GetAsBoolean(&is_p2_undefined);
+
+  EXPECT_FALSE(is_p1_undefined);
+  EXPECT_FALSE(is_p2_undefined);
+}
+
+}  // namespace content