Convert //shell/... to use set_connection_error_handler() instead of set_error_handler().

(The latter is deprecated.)

R=rudominer@chromium.org

Review URL: https://codereview.chromium.org/1219683015 .
diff --git a/shell/application_manager/application_manager.cc b/shell/application_manager/application_manager.cc
index 5da52a7..105ae82 100644
--- a/shell/application_manager/application_manager.cc
+++ b/shell/application_manager/application_manager.cc
@@ -47,7 +47,7 @@
 
 }  // namespace
 
-class ApplicationManager::ContentHandlerConnection : public mojo::ErrorHandler {
+class ApplicationManager::ContentHandlerConnection {
  public:
   ContentHandlerConnection(ApplicationManager* manager,
                            const GURL& content_handler_url)
@@ -61,17 +61,16 @@
         mojo::InterfacePtrInfo<mojo::ContentHandler>(pipe.handle0.Pass(), 0u));
     services->ConnectToService(mojo::ContentHandler::Name_,
                                pipe.handle1.Pass());
-    content_handler_.set_error_handler(this);
+    content_handler_.set_connection_error_handler(
+        [this]() { manager_->OnContentHandlerError(this); });
   }
+  ~ContentHandlerConnection() {}
 
   mojo::ContentHandler* content_handler() { return content_handler_.get(); }
 
   GURL content_handler_url() { return content_handler_url_; }
 
  private:
-  // mojo::ErrorHandler implementation:
-  void OnConnectionError() override { manager_->OnContentHandlerError(this); }
-
   ApplicationManager* manager_;
   GURL content_handler_url_;
   mojo::ContentHandlerPtr content_handler_;