Propagate opener to BackgroundsContents.

components/offline_pages/content/background_loader/background_loader_contents_unittest.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 "components/offline_pages/content/background_loader/background_loader_contents.h"
 
 #include "base/synchronization/waitable_event.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
 
@@ skipping 76 matching lines @@
 
 TEST_F(BackgroundLoaderContentsTest, CannotDownload) {
   contents()->CanDownload(
       GURL::EmptyGURL(), std::string(),
       base::Bind(&BackgroundLoaderContentsTest::DownloadCallback,
                  base::Unretained(this)));
   WaitForSignal();
   ASSERT_FALSE(download());
 }
 
 TEST_F(BackgroundLoaderContentsTest, ShouldNotCreateWebContents) {

[ncarter (slow), 2017/05/17 20:45:27]

Could you also add a few lines to app_background_page_apitest.cc to test the
changes? The idea is to look for consistency between the nullness of
|window.opener| in the background page, and the value of
|WebContents::GetOpener()|.

Near the end of TEST_F(AppBackgroundPageApiTest, NoJsBackgroundPage):

 BackgroundContents* background_contents =
BackgroundContentsServiceFactory::GetForProfile(browser()->profile())->GetAppBackgroundContents(ASCIIToUTF16(extension->id());

 ASSERT_TRUE(background_contents);
 ASSERT_FALSE(background_contents->web_contents()->GetOpener());

[and maybe, also, ExecuteScriptAndExtractBool(web_contents()->GetMainFrame(),
"send(window.opener == null)"]

And do similar but opposite checks in a test w/ js access (is there even one
there?)

[Łukasz Anforowicz, 2017/05/22 17:19:27]

Good idea.  Done.
Note that absence of allow_js_access defaults to true.

OTOH, the only default allow_js_access browser test that pauses after opening a
background page via window.open was disabled.  I cannot repro the flakiness
locally, so I am trying to reenable the test.

   ASSERT_FALSE(contents()->ShouldCreateWebContents(
-      nullptr /* contents */, nullptr /* source_site_instance */,
-      0 /* route_id */, 0 /* main_frame_route_id */,
-      0 /* main_frame_widget_route_id */,
+      nullptr /* contents */, nullptr /* opener */,
+      nullptr /* source_site_instance */, 0 /* route_id */,
+      0 /* main_frame_route_id */, 0 /* main_frame_widget_route_id */,
       content::mojom::WindowContainerType::NORMAL /* window_container_type */,
       GURL() /* opener_url */, "foo" /* frame_name */,
       GURL::EmptyGURL() /* target_url */, "bar" /* partition_id */,
       nullptr /* session_storage_namespace */));
 }
 
 TEST_F(BackgroundLoaderContentsTest, ShouldNotAddNewContents) {
   bool blocked;
   contents()->AddNewContents(
       nullptr /* source */, nullptr /* new_contents */,
@@ skipping 28 matching lines @@
   ASSERT_EQ(nullptr, media_stream_ui());
 }
 
 TEST_F(BackgroundLoaderContentsTest, CheckMediaAccessPermissionFalse) {
   ASSERT_FALSE(contents()->CheckMediaAccessPermission(
       nullptr /* contents */, GURL::EmptyGURL() /* security_origin */,
       content::MediaStreamType::MEDIA_TAB_VIDEO_CAPTURE /* type */));
 }
 
 }  // namespace background_loader