Fixes race condition that could result in a tab prematurely

chrome/browser/renderer_host/render_view_host.h

Index: chrome/browser/renderer_host/render_view_host.h
diff --git a/chrome/browser/renderer_host/render_view_host.h b/chrome/browser/renderer_host/render_view_host.h
index 58b83881dcc818ab38df2664da1614ca2c4761e0..f29669988af1efc08586273c10484b03d140a5ee 100644
--- a/chrome/browser/renderer_host/render_view_host.h
+++ b/chrome/browser/renderer_host/render_view_host.h
@@ -474,6 +474,11 @@ class RenderViewHost : public RenderWidgetHost {
   // in render_messages.h.
   void EnablePreferredSizeChangedMode(int flags);
 
+#if defined(UNIT_TEST)
+  // This shouldn't be necessary outside of testing.
+  bool is_waiting_for_unload_ack() { return is_waiting_for_unload_ack_; }
+#endif
+
  protected:
   // RenderWidgetHost protected overrides.
   virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,