Change userid from a uint32_t to a string guid

components/font_service/font_service_app.h

Index: components/font_service/font_service_app.h
diff --git a/components/font_service/font_service_app.h b/components/font_service/font_service_app.h
index 71d29ccba6852d04c114f0f5d0de48568f981c1f..52b1f030122750e25d4d46803a10873318b7ef0e 100644
--- a/components/font_service/font_service_app.h
+++ b/components/font_service/font_service_app.h
@@ -28,7 +28,7 @@ class FontServiceApp : public mojo::ShellClient,
  private:
   // mojo::ShellClient:
   void Initialize(mojo::Connector* connector, const std::string& url,
-                  uint32_t id, uint32_t user_id) override;
+                  const std::string& user_id, uint32_t id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
   // mojo::InterfaceFactory<FontService>: