mandoline: Make sure omnibox gets updated when navigating back/forwards.

components/web_view/public/interfaces/web_view.mojom

Index: components/web_view/public/interfaces/web_view.mojom
diff --git a/components/web_view/public/interfaces/web_view.mojom b/components/web_view/public/interfaces/web_view.mojom
index d5bab2b4698cd83f35d9a5184d787caebdff923f..1385b8de2d50b4a047e1a6cc2a102108516132e8 100644
--- a/components/web_view/public/interfaces/web_view.mojom
+++ b/components/web_view/public/interfaces/web_view.mojom
@@ -14,7 +14,12 @@ enum ButtonState {
 
 interface WebViewClient {
   // Page-generated request for a top level frame navigation.
-  TopLevelNavigate(mojo.URLRequest request);
+  TopLevelNavigateRequest(mojo.URLRequest request);
+
+  // Notification that the navigation has started. This can be useful for
+  // navigations triggered from sources other than the page itself (e.g.
+  // back/forward history navigation).
+  TopLevelNavigationStarted(string url);
 
   // Loading and progress notifications.
   LoadingStateChanged(bool is_loading, double progress);