PlzNavigate: Create the speculative renderer earlier.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 1d0188516c689326f5f1f6ab0ba62ce80ab90499..519936de9e278ee1a62148e5fa4f13d75a36354a 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -347,6 +347,11 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // PlzNavigate: this call happens on all browser-initiated navigations.
   void DispatchBeforeUnload(bool for_navigation);
 
+  // Returns true if a call to DispatchBeforeUnload will actually send the
+  // BeforeUnload IPC. This is the case if the current renderer is live and this
+  // frame is the main frame.
+  bool ShouldDispatchBeforeUnload();
+
   // Set the frame's opener to null in the renderer process in response to an
   // action in another renderer process.
   void DisownOpener();