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

chrome/browser/chromeos/drive/file_system_unittest.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/chromeos/drive/file_system.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 15 matching lines @@
 #include "chrome/browser/chromeos/drive/test_util.h"
 #include "chrome/browser/drive/fake_drive_service.h"
 #include "chrome/browser/google_apis/drive_api_parser.h"
 #include "chrome/browser/google_apis/test_util.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace drive {
 namespace {
 
-const int64 kLotsOfSpace = internal::kMinFreeSpace * 10;
-
 // Counts the number of invocation, and if it increased up to |expected_counter|
 // quits the current message loop by calling |quit|.
 void AsyncInitializationCallback(
     int* counter, int expected_counter, const base::Closure& quit,
     FileError error, scoped_ptr<ResourceEntry> entry) {
   if (error != FILE_ERROR_OK || !entry) {
     // If we hit an error case, quit the message loop immediately.
     // Then the expectation in the test case can find it because the actual
     // value of |counter| is different from the expected one.
     quit.Run();
@@ skipping 694 matching lines @@
       kEmbedOrigin,
       google_apis::test_util::CreateCopyResultCallback(&error, &share_url));
   test_util::RunBlockingPoolTask();
 
   // Verify the error and the share url, which should be empty.
   EXPECT_EQ(FILE_ERROR_FAILED, error);
   EXPECT_TRUE(share_url.is_empty());
 }
 
 }   // namespace drive