Sort out build dependencies for LinuxUI.

ui/base/linux_ui.cc

Index: ui/base/linux_ui.cc
diff --git a/ui/base/linux_ui.cc b/ui/base/linux_ui.cc
deleted file mode 100644
index 0f9ed4cf5ccc0e10aaf756f1e0e83df28e67a368..0000000000000000000000000000000000000000
--- a/ui/base/linux_ui.cc
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright (c) 2012 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 "ui/base/linux_ui.h"
-
-namespace {
-
-ui::LinuxUI* g_linux_ui = NULL;
-
-}  // namespace
-
-namespace ui {
-
-void LinuxUI::SetInstance(LinuxUI* instance) {
-  delete g_linux_ui;
-  g_linux_ui = instance;
-}
-
-const LinuxUI* LinuxUI::instance() {
-  return g_linux_ui;
-}
-
-}  // namespace ui