Add navigation client lib for convenience

mash/browser/browser.cc

Index: mash/browser/browser.cc
diff --git a/mash/browser/browser.cc b/mash/browser/browser.cc
index c555c9550afc855a694eefb48578000f9232f017..af1b94fc908c3f1cbb3a98af29dc9697fac61a14 100644
--- a/mash/browser/browser.cc
+++ b/mash/browser/browser.cc
@@ -16,6 +16,7 @@
 #include "mash/browser/debug_view.h"
 #include "mash/public/interfaces/launchable.mojom.h"
 #include "mojo/public/c/system/main.h"
+#include "services/navigation/public/cpp/view.h"
 #include "services/navigation/public/interfaces/view.mojom.h"
 #include "services/shell/public/cpp/application_runner.h"
 #include "services/shell/public/cpp/connector.h"
@@ -115,7 +116,7 @@ class Throbber : public views::View {
 class UI : public views::WidgetDelegateView,
            public views::ButtonListener,
            public views::TextfieldController,
-           public navigation::mojom::ViewClient {
+           public navigation::ViewDelegate {
  public:
   enum class Type { WINDOW, POPUP };
 
@@ -276,10 +277,9 @@ class UI : public views::WidgetDelegateView,
     return false;
   }
 
-  // navigation::mojom::ViewClient:
+  // navigation::ViewDelegate:
   void LoadingStateChanged(bool is_loading) override {
-    is_loading_ = is_loading;
-    if (is_loading_) {
+    if (view_.is_loading()) {
       reload_button_->SetText(base::ASCIIToUTF16("Stop"));
       throbber_->Start();
     } else {