chromeos: Use WriteBatch to update DriveResourceMetadata DB

chrome/browser/chromeos/drive/drive_resource_metadata.h

Index: chrome/browser/chromeos/drive/drive_resource_metadata.h
diff --git a/chrome/browser/chromeos/drive/drive_resource_metadata.h b/chrome/browser/chromeos/drive/drive_resource_metadata.h
index 1334deb8cac2054914469548263233a542d0ef97..eb0c27f1141de9edee62fc3232f4b4dbfa49b224 100644
--- a/chrome/browser/chromeos/drive/drive_resource_metadata.h
+++ b/chrome/browser/chromeos/drive/drive_resource_metadata.h
@@ -344,16 +344,10 @@ class DriveResourceMetadata {
   // The method will also do name de-duplication to ensure that the
   // exposed presentation path does not have naming conflicts. Two files with
   // the same name "Foo" will be renames to "Foo (1)" and "Foo (2)".
-  void AddEntryToDirectory(const DriveEntryProto& entry);
+  bool AddEntryToDirectory(const DriveEntryProto& entry);
 
-  // Removes the entry from its parent directory.
-  void RemoveDirectoryChild(const std::string& child_resource_id);
-
-  // Detaches the entry from its parent directory.
-  void DetachEntryFromDirectory(const std::string& child_resource_id);
-
-  // Removes child elements of directory.
-  void RemoveDirectoryChildren(const std::string& directory_resource_id);
+  // Removes the entry and its descendants.
+  bool RemoveEntryRecursively(const std::string& resource_id);
 
   // Converts the children as a vector of DriveEntryProto.
   scoped_ptr<DriveEntryProtoVector> DirectoryChildrenToProtoVector(