Revert of Reland: Create hard links in file migration if necessary.

components/drive/file_cache.cc

Index: components/drive/file_cache.cc
diff --git a/components/drive/file_cache.cc b/components/drive/file_cache.cc
index c9ceb105f7133c5eac0ad7f6863756be339c0ebe..73d28d41064dc77d66a82bd227994b750e96d1b0 100644
--- a/components/drive/file_cache.cc
+++ b/components/drive/file_cache.cc
@@ -3,8 +3,6 @@
 // found in the LICENSE file.
 
 #include "components/drive/file_cache.h"
-
-#include <unistd.h>
 
 #include <queue>
 #include <vector>
@@ -683,8 +681,7 @@
 
 // static
 bool FileCache::MigrateCacheFiles(const base::FilePath& from,
-                                  const base::FilePath& to_files,
-                                  const base::FilePath& to_links,
+                                  const base::FilePath& to,
                                   ResourceMetadataStorage* metadata_storage) {
   scoped_ptr<ResourceMetadataStorage::Iterator> it =
       metadata_storage->GetIterator();
@@ -694,31 +691,17 @@
       continue;
     }
 
-    // Ignore missing cache file case since it never succeeds.
-    // TODO(yawano): handle this case at metadata validation in FileCache.
     const base::FilePath move_from = GetPathForId(from, entry.local_id());
     if (!base::PathExists(move_from)) {
       continue;
     }
 
-    // Create hard link to cache file if it's pinned or dirty. cryptohome will
-    // not delete a cache file if there is a hard link to it.
-    const FileCacheEntry& file_cache_entry =
-        entry.file_specific_info().cache_state();
-    if (file_cache_entry.is_pinned() || file_cache_entry.is_dirty()) {
-      const base::FilePath link_path = GetPathForId(to_links, entry.local_id());
-      int link_result = link(move_from.AsUTF8Unsafe().c_str(),
-                             link_path.AsUTF8Unsafe().c_str());
-      if (link_result != 0 && errno != EEXIST) {
-        return false;
-      }
-    }
-
-    // Move cache file.
-    const base::FilePath move_to = GetPathForId(to_files, entry.local_id());
+    const base::FilePath move_to = GetPathForId(to, entry.local_id());
     if (!base::Move(move_from, move_to)) {
       return false;
     }
+
+    // TODO(yawano): create hard link if entry is marked as pinned or dirty.
   }
 
   return true;