Remove unused fields found by clang's new Wunused-private-fields.

webkit/fileapi/obfuscated_file_util_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 <algorithm>
 #include <set>
 #include <string>
 
 #include "base/bind.h"
 #include "base/file_path.h"
@@ skipping 327 matching lines @@
     }
 
    private:
     void Check() {
       ASSERT_EQ(expected_usage_,
                 test_helper_->GetCachedOriginUsage());
     }
 
     scoped_ptr<FileSystemOperationContext> context_;
     FileSystemTestOriginHelper* test_helper_;
-    int64 growth_;
     int64 expected_usage_;
   };
 
   scoped_ptr<UsageVerifyHelper> AllowUsageIncrease(int64 requested_growth) {
     int64 usage = test_helper_.GetCachedOriginUsage();
     return scoped_ptr<UsageVerifyHelper>(new UsageVerifyHelper(
         LimitedContext(requested_growth),
         &test_helper_, usage + requested_growth));
   }
 
@@ skipping 1829 matching lines @@
 
   // Opening it with TRUNCATED flag, which should truncate the file size.
   ASSERT_EQ(base::PLATFORM_FILE_OK,
             ofu()->CreateOrOpen(
                 AllowUsageIncrease(-length)->context(), file,
                 base::PLATFORM_FILE_OPEN_TRUNCATED | base::PLATFORM_FILE_WRITE,
                 &file_handle, &created));
   ASSERT_EQ(0, ComputeTotalFileSize());
   EXPECT_TRUE(base::ClosePlatformFile(file_handle));
 }