linux and chromeos: Turn on -Wunused-const-variable.

chrome/browser/apps/app_browsertest.cc

 // Copyright 2013 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 "apps/launcher.h"
 #include "apps/shell_window.h"
 #include "apps/shell_window_registry.h"
 #include "apps/ui/native_app_window.h"
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 169 matching lines @@
   base::FilePath path = temp_dir.AppendASCII(
       filename).NormalizePathSeparators();
   if (!(base::CopyFile(test_data_file, path)))
     return false;
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   command_line->AppendArgPath(path);
   return true;
 }
 
+#if !defined(OS_CHROMEOS)
 const char kTestFilePath[] = "platform_apps/launch_files/test.txt";
+#endif
 
 }  // namespace
 
 // Tests that CreateShellWindow doesn't crash if you close it straight away.
 // LauncherPlatformAppBrowserTest relies on this behaviour, but is only run for
 // ash, so we test that it works here.
 IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, CreateAndCloseShellWindow) {
   const Extension* extension = LoadAndLaunchPlatformApp("minimal");
   ShellWindow* window = CreateShellWindow(extension);
   CloseShellWindow(window);
@@ skipping 1092 matching lines @@
                                                           false);
   ASSERT_TRUE(restart_requested_listener.WaitUntilSatisfied());
 
   EXPECT_EQ(1, request_restart_call_count());
 }
 
 #endif  // defined(OS_CHROMEOS)
 
 
 }  // namespace extensions