gdata: Fix issue with copying hosted documents out from Docs folder.

chrome/browser/chromeos/gdata/gdata_file_system.h

Index: chrome/browser/chromeos/gdata/gdata_file_system.h
===================================================================
--- chrome/browser/chromeos/gdata/gdata_file_system.h	(revision 128786)
+++ chrome/browser/chromeos/gdata/gdata_file_system.h	(working copy)
@@ -349,6 +349,10 @@
   // <user_profile_dir>/GCache/v1/pinned
   virtual FilePath GetGDataCachePersistentDirectory() const = 0;
 
+  // Returns the directory for hosting temporary document JSON files, i.e.
+  // <system_temp_dir>/<unique_temp_dir>
+  virtual FilePath GetGDataTempDocumentDirectory() const = 0;
+
   // Returns absolute path of the file if it were cached or to be cached.
   virtual FilePath GetCacheFilePath(
       const std::string& resource_id,
@@ -426,6 +430,7 @@
   virtual FilePath GetGDataTempDownloadFolderPath() const OVERRIDE;
   virtual FilePath GetGDataCachePinnedDirectory() const OVERRIDE;
   virtual FilePath GetGDataCachePersistentDirectory() const OVERRIDE;
+  virtual FilePath GetGDataTempDocumentDirectory() const OVERRIDE;
   virtual FilePath GetCacheFilePath(
       const std::string& resource_id,
       const std::string& md5,
@@ -585,10 +590,11 @@
                                  base::PlatformFileError *error);
 
   // Creates a temporary JSON file representing a document with |edit_url|
-  // and |resource_id| on IO thread pool. Upon completion it will invoke
-  // |callback| with the path of the created temporary file on thread
-  // represented by |relay_proxy|.
+  // and |resource_id| under |document_dir| on IO thread pool. Upon completion
+  // it will invoke |callback| with the path of the created temporary file on
+  // thread represented by |relay_proxy|.
   static void CreateDocumentJsonFileOnIOThreadPool(
+      const FilePath& document_dir,
       const GURL& edit_url,
       const std::string& resource_id,
       const GetFileCallback& callback,
@@ -1155,6 +1161,9 @@
   // GDataRootDirectory::CacheSubDirectoryType enum.
   std::vector<FilePath> cache_paths_;
 
+  // Directory for hosting temporary document JSON files.
+  FilePath temp_document_dir_;
+
   scoped_ptr<base::WaitableEvent> on_io_completed_;
 
   // True if cache initialization has started, is in progress or has completed,