Propagate opener to BackgroundsContents.

components/offline_pages/content/background_loader/background_loader_contents_unittest.cc

Index: components/offline_pages/content/background_loader/background_loader_contents_unittest.cc
diff --git a/components/offline_pages/content/background_loader/background_loader_contents_unittest.cc b/components/offline_pages/content/background_loader/background_loader_contents_unittest.cc
index 3a31cce519025db801b04ed56ba2ec410071fa63..3cfae2c2bc1024d2a548b0ca63fb3ab196f1c7ce 100644
--- a/components/offline_pages/content/background_loader/background_loader_contents_unittest.cc
+++ b/components/offline_pages/content/background_loader/background_loader_contents_unittest.cc
@@ -96,9 +96,9 @@ TEST_F(BackgroundLoaderContentsTest, CannotDownload) {
 
 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 */,