Exclude building signin view controller and its delegate on ChromeOS

chrome/browser/ui/signin_view_controller_chromeos.cc

+// Copyright 2017 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 "chrome/browser/ui/signin_view_controller.h"
+
+#include "base/logging.h"
+// Empty implementation on ChromeOS as this class should not be used on
+// ChromeOS.
+SigninViewController::SigninViewController()
+    : signin_view_controller_delegate_(nullptr) {}
+
+SigninViewController::~SigninViewController() {}
+
+void SigninViewController::ShowModalSignin(
+    profiles::BubbleViewMode mode,
+    Browser* browser,
+    signin_metrics::AccessPoint access_point) {
+  NOTREACHED();
+}
+
+void SigninViewController::ShowModalSyncConfirmationDialog(Browser* browser) {
+  NOTREACHED();
+}
+
+void SigninViewController::ShowModalSigninErrorDialog(Browser* browser) {
+  NOTREACHED();
+}
+
+void SigninViewController::CloseModalSignin() {
+  NOTREACHED();
+}
+
+void SigninViewController::SetModalSigninHeight(int height) {
+  NOTREACHED();
+}
+
+void SigninViewController::ResetModalSigninDelegate() {
+  NOTREACHED();
+}
+
+// static
+bool SigninViewController::ShouldShowModalSigninForMode(
+    profiles::BubbleViewMode mode) {
+  NOTREACHED();
+  return false;
+}