Cleanup blink-side PlzNavigate logic

third_party/WebKit/Source/core/loader/NavigationScheduler.cpp

Index: third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
diff --git a/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp b/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
index ce336c4ac00f4173044f72a0dab7c67b70c20cc8..0e3588c5f00bab67cee834328bb215a77318fc90 100644
--- a/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
+++ b/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
@@ -496,7 +496,8 @@ void NavigationScheduler::schedule(ScheduledNavigation* redirect) {
   // location change. Let the JS have its way.
   // FIXME: This check seems out of place.
   if (!m_frame->loader().stateMachine()->committedFirstRealDocumentLoad() &&
-      m_frame->loader().provisionalDocumentLoader()) {
+      m_frame->loader().provisionalDocumentLoader() &&
+      m_frame->loader().provisionalDocumentLoader()->didStart()) {
     m_frame->loader().stopAllLoaders();
     if (!m_frame->host())
       return;