Files.app: Show thumbnail of non-image file even when the file cache is present

ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js

Index: ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js
diff --git a/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js b/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js
index 1293881f64baae99d0efd4dc25e23910cfe098b1..29805735208f05a532461ec164c99905a0dda56f 100644
--- a/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js
+++ b/ui/file_manager/file_manager/foreground/js/metadata/metadata_cache.js
@@ -873,7 +873,8 @@ ExternalProvider.prototype.convert_ = function(data, entry) {
     customIconUrl: data.customIconUrl || '',
     contentMimeType: data.contentMimeType || '',
     sharedWithMe: data.sharedWithMe,
-    shared: data.shared
+    shared: data.shared,
+    thumbnailUrl: data.thumbnailUrl  // Thumbnail passed from external server.

[mtomasz, 2014/09/17 09:29:48]

ExternalProvider used to provide a thumbnail field if the file is not cached.
See #804. However, after this change it's not. Calling
metadataCache.get([entry], 'thumbnail') would skip the ExternalProvider and
cause downloading the entire file to get a thumbnail from file if it's not
cached, what may kill performance of the grid view and mosaic view.

[yoshiki, 2014/09/17 09:57:09]

I got it. I add the code to fill thumbnail field when the file is present below.

   };
 
   result.filesystem = {
@@ -881,18 +882,6 @@ ExternalProvider.prototype.convert_ = function(data, entry) {
     modificationTime: new Date(data.lastModifiedTime)
   };
 
-  if ('thumbnailUrl' in data) {
-    result.thumbnail = {
-      url: data.thumbnailUrl,
-      transform: null
-    };
-  } else if (data.isPresent) {
-    result.thumbnail = null;
-  } else {
-    // Not present in cache, so do not allow to generate it by next providers.
-    result.thumbnail = {url: '', transform: null};
-  }
-
   // If present in cache, then allow to fetch media by next providers.
   result.media = data.isPresent ? null : {};