Set user_gesture bit at NavigationHandle creation time.

content/browser/frame_host/interstitial_page_navigator_impl.h

Index: content/browser/frame_host/interstitial_page_navigator_impl.h
diff --git a/content/browser/frame_host/interstitial_page_navigator_impl.h b/content/browser/frame_host/interstitial_page_navigator_impl.h
index 92afa5f07889d14bacc5eb579b3dc2d6caa11d76..f9bd7a873b7d01349e68ad1dd369e98aae3ededb 100644
--- a/content/browser/frame_host/interstitial_page_navigator_impl.h
+++ b/content/browser/frame_host/interstitial_page_navigator_impl.h
@@ -26,10 +26,10 @@ class CONTENT_EXPORT InterstitialPageNavigatorImpl : public Navigator {
 
   NavigatorDelegate* GetDelegate() override;
   NavigationController* GetController() override;
-  void DidStartProvisionalLoad(
-      RenderFrameHostImpl* render_frame_host,
-      const GURL& url,
-      const base::TimeTicks& navigation_start) override;
+  void DidStartProvisionalLoad(RenderFrameHostImpl* render_frame_host,
+                               const GURL& url,
+                               const base::TimeTicks& navigation_start,
+                               NavigationGesture gesture) override;
   void DidNavigate(
       RenderFrameHostImpl* render_frame_host,
       const FrameHostMsg_DidCommitProvisionalLoad_Params& input_params,