Make `chrome` target build without unused data members on Linux.

chrome/browser/password_manager/native_backend_gnome_x.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 "chrome/browser/password_manager/native_backend_gnome_x.h"
 
 #include <dlfcn.h>
 #include <gnome-keyring.h>
 #include <stddef.h>
 #include <stdint.h>
@@ skipping 508 matching lines @@
 std::string GetProfileSpecificAppString(LocalProfileId profile_id) {
   // Originally, the application string was always just "chrome" and used only
   // so that we had *something* to search for since GNOME Keyring won't search
   // for nothing. Now we use it to distinguish passwords for different profiles.
   return base::StringPrintf("%s-%d", kGnomeKeyringAppString, profile_id);
 }
 
 }  // namespace
 
 NativeBackendGnome::NativeBackendGnome(LocalProfileId id)
-    : profile_id_(id), app_string_(GetProfileSpecificAppString(id)) {
+    : app_string_(GetProfileSpecificAppString(id)) {
 }
 
 NativeBackendGnome::~NativeBackendGnome() {
 }
 
 bool NativeBackendGnome::Init() {
   return LoadGnomeKeyring() && gnome_keyring_is_available();
 }
 
 bool NativeBackendGnome::RawAddLogin(const PasswordForm& form) {
@@ skipping 262 matching lines @@
   ScopedVector<PasswordForm> forms;
   if (!GetLoginsBetween(get_begin, get_end, date_to_compare, &forms))
     return false;
 
   for (size_t i = 0; i < forms.size(); ++i) {
     if (!RemoveLogin(*forms[i], changes))
       return false;
   }
   return true;
 }