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..ddc1d3b3284e707cfecfe7aef1953ac2652f82c9 100644
--- a/content/public/test/content_browser_test_utils.cc
+++ b/content/public/test/content_browser_test_utils.cc
@@ -8,6 +8,7 @@
 #include "base/files/file_path.h"
 #include "base/path_service.h"
 #include "base/run_loop.h"
+#include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/web_contents.h"
@@ -17,6 +18,7 @@
 #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 +58,12 @@ void NavigateToURL(Shell* window, const GURL& url) {
   NavigateToURLBlockUntilNavigationsComplete(window, url, 1);
 }
 
+void NavigateFrameToURL(RenderFrameHostImpl* rfh, const GURL& url) {
+  TestFrameNavigationObserver observer(rfh);
+  rfh->NavigateToURL(url);

[Charlie Reis, 2014/04/24 20:37:50]

Hmm, I'm not sure we want to use RFH::NavigateToURL, do we?  Seems like it would
be more representative to go through NavigationController::LoadURLWithParams, as
in
https://codereview.chromium.org/209153003/diff/1/content/browser/site_per_pro....
 Does that have problems?

Similarly, I'm uncertain if we want this method to take in a RFH or a
FrameTreeNode.  I don't think we would want people trying to navigate RFHs that
aren't the current RFH, for example.

[nasko, 2014/04/24 22:31:12]

Done.

+  observer.Wait();
+}
+
 void WaitForAppModalDialog(Shell* window) {
   ShellJavaScriptDialogManager* dialog_manager=
       static_cast<ShellJavaScriptDialogManager*>(