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

chrome/browser/chromeos/drive/file_cache_metadata_unittest.cc

Index: chrome/browser/chromeos/drive/file_cache_metadata_unittest.cc
diff --git a/chrome/browser/chromeos/drive/file_cache_metadata_unittest.cc b/chrome/browser/chromeos/drive/file_cache_metadata_unittest.cc
index 804e7c5d50fe33cf5cbea2a59b273e20608c2220..7ceadf6d259ec8a629e3e15a8afbd9dc38ee58ad 100644
--- a/chrome/browser/chromeos/drive/file_cache_metadata_unittest.cc
+++ b/chrome/browser/chromeos/drive/file_cache_metadata_unittest.cc
@@ -17,18 +17,12 @@ namespace internal {
 
 class FileCacheMetadataTest : public testing::Test {
  public:
-  FileCacheMetadataTest() {}
-
   virtual void SetUp() OVERRIDE {
     // Create cache directories.
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
     metadata_.reset(new FileCacheMetadata(NULL));
   }
 
-  virtual void TearDown() OVERRIDE {
-    metadata_.reset();
-  }
-
  protected:
   base::ScopedTempDir temp_dir_;
   scoped_ptr<FileCacheMetadata> metadata_;