[fsp] Move thumbnail logic to Drive specific C++ code.

chrome/browser/chromeos/extensions/file_manager/private_api_drive.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/extensions/file_manager/private_api_drive.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/drive/drive_integration_service.h"
 #include "chrome/browser/chromeos/extensions/file_manager/private_api_util.h"
@@ skipping 53 matching lines @@
   properties->file_size.reset(new double(file_info.size()));
   properties->last_modified_time.reset(new double(
       base::Time::FromInternalValue(file_info.last_modified()).ToJsTime()));
 
   if (!entry_proto.has_file_specific_info())
     return;
 
   const drive::FileSpecificInfo& file_specific_info =
       entry_proto.file_specific_info();
 
-  if (!entry_proto.resource_id().empty()) {
+  // The web thumbnail is used only when the file is not present. Otherwise
+  // it could be out of sync.
+  if (!entry_proto.resource_id().empty() &&
+      !file_specific_info.cache_state().is_present()) {
     properties->thumbnail_url.reset(
         new std::string("https://www.googledrive.com/thumb/" +
                         entry_proto.resource_id() + "?width=500&height=500"));
   }
   if (file_specific_info.has_image_width()) {
     properties->image_width.reset(
         new int(file_specific_info.image_width()));
   }
   if (file_specific_info.has_image_height()) {
     properties->image_height.reset(
@@ skipping 890 matching lines @@
     return;
   }
 
   const std::string url = download_url_ + "?access_token=" + access_token;
   SetResult(new base::StringValue(url));
 
   SendResponse(true);
 }
 
 }  // namespace extensions