Pass the final URL an app was loaded from to the app in Initialize().

examples/forwarding_content_handler/forwarding_content_handler.cc

Index: examples/forwarding_content_handler/forwarding_content_handler.cc
diff --git a/examples/forwarding_content_handler/forwarding_content_handler.cc b/examples/forwarding_content_handler/forwarding_content_handler.cc
index b424eb79277b1e6ef62508a3d1c59e2af166a749..8718a6e7399ca0974d215e8a70e0563304a793a6 100644
--- a/examples/forwarding_content_handler/forwarding_content_handler.cc
+++ b/examples/forwarding_content_handler/forwarding_content_handler.cc
@@ -29,7 +29,9 @@ class ForwardingApplicationImpl : public Application {
 
  private:
   // Application:
-  void Initialize(ShellPtr shell, Array<String> args) override {
+  void Initialize(ShellPtr shell,
+                  const mojo::String& url,
+                  Array<String> args) override {
     shell_ = shell.Pass();
   }
   void AcceptConnection(const String& requestor_url,