Fixes race condition that could result in a tab prematurely

chrome/browser/renderer_host/render_view_host.cc

Index: chrome/browser/renderer_host/render_view_host.cc
diff --git a/chrome/browser/renderer_host/render_view_host.cc b/chrome/browser/renderer_host/render_view_host.cc
index 0ba65d66c207139841a9875880d6c08576c64673..6eb899956513ca59da6f4daaf870fe3c1c4e5e10 100644
--- a/chrome/browser/renderer_host/render_view_host.cc
+++ b/chrome/browser/renderer_host/render_view_host.cc
@@ -243,6 +243,10 @@ void RenderViewHost::Navigate(const ViewMsg_Navigate_Params& params) {
     DCHECK(!suspended_nav_message_.get());
     suspended_nav_message_.reset(nav_message);
   } else {
+    // Unset this, otherwise if true and the hang monitor fires we'll
+    // incorrectly close the tab.
+    is_waiting_for_unload_ack_ = false;
+
     Send(nav_message);
 
     // Force the throbber to start. We do this because WebKit's "started