Remove destruction-only TearDown() methods in Drive related test.

chrome/browser/chromeos/drive/file_cache_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_cache.h"
 
 #include <string>
 #include <vector>
 
 #include "base/file_util.h"
@@ skipping 891 matching lines @@
     ASSERT_TRUE(metadata_storage_->Initialize());
 
     cache_.reset(new FileCache(
         metadata_storage_.get(),
         temp_dir_.path().Append(util::kCacheFileDirectory),
         base::MessageLoopProxy::current(),
         fake_free_disk_space_getter_.get()));
     ASSERT_TRUE(cache_->Initialize());
   }
 
-  virtual void TearDown() OVERRIDE {
-    cache_.reset();
-  }
-
   static bool ImportOldDB(FileCache* cache, const base::FilePath& old_db_path) {
     return cache->ImportOldDB(old_db_path);
   }
 
   content::TestBrowserThreadBundle thread_bundle_;
   base::ScopedTempDir temp_dir_;
 
   scoped_ptr<ResourceMetadataStorage, test_util::DestroyHelperForTests>
       metadata_storage_;
   scoped_ptr<FileCache, test_util::DestroyHelperForTests> cache_;
@@ skipping 115 matching lines @@
   // Data is imported correctly.
   FileCacheEntry entry;
   EXPECT_TRUE(cache_->GetCacheEntry(key1, std::string(), &entry));
   EXPECT_EQ(md5_1, entry.md5());
   EXPECT_TRUE(cache_->GetCacheEntry(key2, std::string(), &entry));
   EXPECT_EQ(md5_2, entry.md5());
 }
 
 }  // namespace internal
 }  // namespace drive