Perform navigation policy check on UI thread for --site-per-process.

content/public/test/content_browser_test_utils.cc

Index: content/public/test/content_browser_test_utils.cc
diff --git a/content/public/test/content_browser_test_utils.cc b/content/public/test/content_browser_test_utils.cc
index d9448f0fc4dd1808653208cb83b890efce18d48d..376705e19b52c3020c8287eed1304109d4f139b7 100644
--- a/content/public/test/content_browser_test_utils.cc
+++ b/content/public/test/content_browser_test_utils.cc
@@ -8,6 +8,8 @@
 #include "base/files/file_path.h"
 #include "base/path_service.h"
 #include "base/run_loop.h"
+#include "content/browser/frame_host/frame_tree_node.h"
+#include "content/browser/frame_host/navigator.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/web_contents.h"
@@ -17,6 +19,7 @@
 #include "content/public/test/test_utils.h"
 #include "content/shell/browser/shell.h"
 #include "content/shell/browser/shell_javascript_dialog_manager.h"
+#include "content/test/test_frame_navigation_observer.h"
 #include "net/base/filename_util.h"
 
 namespace content {
@@ -56,6 +59,15 @@ void NavigateToURL(Shell* window, const GURL& url) {
   NavigateToURLBlockUntilNavigationsComplete(window, url, 1);
 }
 
+void NavigateFrameToURL(FrameTreeNode* node, const GURL& url) {
+  TestFrameNavigationObserver observer(node);
+  NavigationController::LoadURLParams params(url);
+  params.transition_type = PageTransitionFromInt(PAGE_TRANSITION_LINK);
+  params.frame_tree_node_id = node->frame_tree_node_id();
+  node->navigator()->GetController()->LoadURLWithParams(params);
+  observer.Wait();
+}
+
 void WaitForAppModalDialog(Shell* window) {
   ShellJavaScriptDialogManager* dialog_manager=
       static_cast<ShellJavaScriptDialogManager*>(