Fix CrossProcessPopupInheritsSandboxFlagsWithNoOpener on M50 official builds.

content/browser/frame_host/render_frame_host_manager_browsertest.cc

Index: content/browser/frame_host/render_frame_host_manager_browsertest.cc
diff --git a/content/browser/frame_host/render_frame_host_manager_browsertest.cc b/content/browser/frame_host/render_frame_host_manager_browsertest.cc
index 6b06f8bb274498d69b944f935badb678f36604a3..ca6ea42eb9fdfff67f5173a66d834f08bddd93f3 100644
--- a/content/browser/frame_host/render_frame_host_manager_browsertest.cc
+++ b/content/browser/frame_host/render_frame_host_manager_browsertest.cc
@@ -2513,6 +2513,7 @@ IN_PROC_BROWSER_TEST_F(RenderFrameHostManagerTest,
   GURL frame_url(
       embedded_test_server()->GetURL("a.com", "/click-noreferrer-links.html"));
   NavigateFrameToURL(root->child_at(0), frame_url);
+  EXPECT_TRUE(WaitForLoadStop(shell()->web_contents()));
   std::string script = "setOriginForLinks('http://b.com:" +
                        embedded_test_server()->base_url().port() + "/');";
   EXPECT_TRUE(ExecuteScript(root->child_at(0)->current_frame_host(), script));