Expose loading state from Blimp to Tab

blimp/client/core/contents/blimp_navigation_controller_impl.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "blimp/client/core/contents/blimp_navigation_controller_impl.h"
 
 #include "blimp/client/core/contents/blimp_navigation_controller_delegate.h"
 
 namespace {
 // TODO(shaktisahu): NavigationFeature currently needs a tab_id. Remove this
@@ skipping 60 matching lines @@
 }
 
 void BlimpNavigationControllerImpl::OnTitleChanged(int tab_id,
                                                    const std::string& title) {
   current_title_ = title;
   delegate_->OnNavigationStateChanged();
 }
 
 void BlimpNavigationControllerImpl::OnLoadingChanged(int tab_id, bool loading) {
   delegate_->OnNavigationStateChanged();
+  delegate_->OnLoadingStateChanged(loading);
 }
 
 void BlimpNavigationControllerImpl::OnPageLoadStatusUpdate(int tab_id,
                                                            bool completed) {
   delegate_->OnNavigationStateChanged();
 }
 
 }  // namespace client
 }  // namespace blimp