Remove Clone() from CannedBrowsingData*Helper classes

chrome/browser/browsing_data/browsing_data_file_system_helper.cc

Index: chrome/browser/browsing_data/browsing_data_file_system_helper.cc
diff --git a/chrome/browser/browsing_data/browsing_data_file_system_helper.cc b/chrome/browser/browsing_data/browsing_data_file_system_helper.cc
index f89c7955dc2e4950a8718e6a8a228f5b33ded478..5138b2a489ff0c58ea2d58729161faa6fbed1794 100644
--- a/chrome/browser/browsing_data/browsing_data_file_system_helper.cc
+++ b/chrome/browser/browsing_data/browsing_data_file_system_helper.cc
@@ -194,22 +194,8 @@ CannedBrowsingDataFileSystemHelper::CannedBrowsingDataFileSystemHelper(
     Profile* profile) {
 }
 
-CannedBrowsingDataFileSystemHelper::CannedBrowsingDataFileSystemHelper() {
-}
-
 CannedBrowsingDataFileSystemHelper::~CannedBrowsingDataFileSystemHelper() {}
 
-CannedBrowsingDataFileSystemHelper*
-    CannedBrowsingDataFileSystemHelper::Clone() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  CannedBrowsingDataFileSystemHelper* clone =
-      new CannedBrowsingDataFileSystemHelper();
-  // This list only mutates on the UI thread, so it's safe to work with it here
-  // (given the DCHECK above).
-  clone->file_system_info_ = file_system_info_;
-  return clone;
-}
-
 void CannedBrowsingDataFileSystemHelper::AddFileSystem(
     const GURL& origin,
     const storage::FileSystemType type,