gdata: Convert public synchronous functions in GDataFileSystem to asynchronous.

chrome/browser/chromeos/gdata/gdata_file_system_proxy.h

Index: chrome/browser/chromeos/gdata/gdata_file_system_proxy.h
diff --git a/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h b/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h
index d5101028a22054bd2e57ccab5d4f990a229897fd..4d5595fe4af35a3c9fe939a6d68bd7eeb88e8160 100644
--- a/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h
+++ b/chrome/browser/chromeos/gdata/gdata_file_system_proxy.h
@@ -69,6 +69,15 @@ class GDataFileSystemProxy : public fileapi::RemoteFileSystemProxyInterface {
       const FilePath& entry_path,
       scoped_ptr<gdata::GDataEntryProto> entry_proto);
 
+  // Helper callback for relaying reply for GetEntryInfoByPathAsync() to the
+  // calling thread.
+  void OnGetEntryInfoByPathAsync(
+      const fileapi::FileSystemOperationInterface::SnapshotFileCallback&
+          callback,
+      base::PlatformFileError error,
+      const FilePath& entry_path,
+      scoped_ptr<GDataEntryProto> entry_proto);
+
   // Helper callback for relaying reply for ReadDirectory() to the calling
   // thread.
   void OnReadDirectory(