Enable --nacl-gdb flag on Linux.

chrome/browser/nacl_host/test/nacl_gdb_browsertest.cc

 // 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 "base/command_line.h"
 #include "base/environment.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/win/windows_version.h"
 #include "chrome/common/chrome_switches.h"
@@ skipping 24 matching lines @@
 IN_PROC_BROWSER_TEST_F(NaClGdbTest, Empty) {
   FilePath mock_nacl_gdb_file;
   scoped_ptr<base::Environment> env(base::Environment::Create());
   std::string content;
   // TODO(halyavin): Make this test to work on Windows 32-bit. Currently this
   // is not possible because NaCl doesn't work without sandbox since 1Gb of
   // space is not reserved. We can't reserve 1Gb of space because
   // base::LaunchProcess doesn't support creating suspended processes. We need
   // to either add suspended process support to base::LaunchProcess or use
   // Win API.
+#if defined(OS_WIN)
   if (base::win::OSInfo::GetInstance()->wow64_status() ==
       base::win::OSInfo::WOW64_DISABLED) {
     return;
   }
+#endif
   EXPECT_TRUE(file_util::CreateTemporaryFile(&mock_nacl_gdb_file));
   env->SetVar("MOCK_NACL_GDB", mock_nacl_gdb_file.AsUTF8Unsafe());
   RunTestViaHTTP("Empty");
   env->UnSetVar("MOCK_NACL_GDB");
   EXPECT_TRUE(file_util::ReadFileToString(mock_nacl_gdb_file, &content));
   EXPECT_STREQ("PASS", content.c_str());
   EXPECT_TRUE(file_util::Delete(mock_nacl_gdb_file, false));
 }