Files.app: Stop to use drive thumbnail for cached files.

ui/file_manager/file_manager/foreground/js/thumbnail_loader.js

Index: ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
diff --git a/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js b/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
index a9fa132e7fdf0867a45f8ccd8ce1b2b349188e6c..0580e1dafaf80e0da72c9529756b05a6905bbae5 100644
--- a/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
+++ b/ui/file_manager/file_manager/foreground/js/thumbnail_loader.js
@@ -12,14 +12,19 @@
  *     default: IMAGE.
  * @param {Object=} opt_metadata Metadata object.
  * @param {string=} opt_mediaType Media type.
- * @param {ThumbnailLoader.UseEmbedded=} opt_useEmbedded If to use embedded
- *     jpeg thumbnail if available. Default: USE_EMBEDDED.
+ * @param {Array<ThumbnailLoader.LoadTarget>=} opt_loadTargets The list of load
+ *     targets in preferential order. The default value is [CONTENT_METADATA,
+ *     EXTERNAL_METADATA, FILE_ENTRY].
  * @param {number=} opt_priority Priority, the highest is 0. default: 2.
  * @constructor
  */
 function ThumbnailLoader(entry, opt_loaderType, opt_metadata, opt_mediaType,
-    opt_useEmbedded, opt_priority) {
-  opt_useEmbedded = opt_useEmbedded || ThumbnailLoader.UseEmbedded.USE_EMBEDDED;
+    opt_loadTargets, opt_priority) {
+  var loadTargets = opt_loadTargets || [
+    ThumbnailLoader.LoadTarget.CONTENT_METADATA,
+    ThumbnailLoader.LoadTarget.EXTERNAL_METADATA,
+    ThumbnailLoader.LoadTarget.FILE_ENTRY
+  ];
 
   this.mediaType_ = opt_mediaType || FileType.getMediaType(entry);
   this.loaderType_ = opt_loaderType || ThumbnailLoader.LoaderType.IMAGE;
@@ -27,8 +32,15 @@ function ThumbnailLoader(entry, opt_loaderType, opt_metadata, opt_mediaType,
   this.priority_ = (opt_priority !== undefined) ? opt_priority : 2;
   this.transform_ = null;
 
+  /**
+   * @type {?ThumbnailLoader.LoadTarget}
+   * @private
+   */
+  this.loadTarget_ = null;
+
   if (!opt_metadata) {
     this.thumbnailUrl_ = entry.toURL();  // Use the URL directly.
+    this.loadTarget_ = ThumbnailLoader.LoadTarget.FILE_ENTRY;
     return;
   }
 
@@ -37,20 +49,39 @@ function ThumbnailLoader(entry, opt_loaderType, opt_metadata, opt_mediaType,
   if (opt_metadata.external && opt_metadata.external.customIconUrl)
     this.fallbackUrl_ = opt_metadata.external.customIconUrl;
 
-  if (ThumbnailLoader.hasThumbnailInMetadata(opt_metadata) &&
-      opt_useEmbedded === ThumbnailLoader.UseEmbedded.USE_EMBEDDED) {
-    // If the thumbnail generated from the local cache (metadata.thumbnail.url)
-    // is available, use it. If not, use the one passed from the external
-    // provider (metadata.external.thumbnailUrl).
-    this.thumbnailUrl_ =
-        (opt_metadata.thumbnail && opt_metadata.thumbnail.url) ||
-        (opt_metadata.external && opt_metadata.external.thumbnailUrl);
-    this.transform_ =
-        opt_metadata.thumbnail && opt_metadata.thumbnail.transform;
-  } else if (FileType.isImage(entry)) {
-    this.thumbnailUrl_ = entry.toURL();
-    this.transform_ = opt_metadata.media && opt_metadata.media.imageTransform;
-  } else if (this.fallbackUrl_) {
+  for (var i = 0; i < loadTargets.length; i++) {
+    switch (loadTargets[i]) {
+      case ThumbnailLoader.LoadTarget.CONTENT_METADATA:
+        if (opt_metadata.thumbnail && opt_metadata.thumbnail.url) {
+          this.thumbnailUrl_ = opt_metadata.thumbnail.url;
+          this.thumbnailTransform =
+              opt_metadata.thumbnail && opt_metadata.thumbnail.transform;
+          this.loadTarget_ = ThumbnailLoader.LoadTarget.CONTENT_METADATA;
+        }
+        break;
+      case ThumbnailLoader.LoadTarget.EXTERNAL_METADATA:
+        if (opt_metadata.external && opt_metadata.external.thumbnailUrl &&
+            (!opt_metadata.external.dirty || !FileType.isImage(entry))) {
+          this.thumbnailUrl_ = opt_metadata.external.thumbnailUrl;
+          this.loadTarget_ = ThumbnailLoader.LoadTarget.EXTERNAL_METADATA;
+        }
+        break;
+      case ThumbnailLoader.LoadTarget.FILE_ENTRY:
+        if (FileType.isImage(entry)) {
+          this.thumbnailUrl_ = entry.toURL();
+          this.transform_ =
+              opt_metadata.media && opt_metadata.media.imageTransform;
+          this.loadTarget_ = ThumbnailLoader.LoadTarget.FILE_ENTRY;
+        }
+        break;
+      default:
+        assertNotReached('Unkonwn load type: ' + loadTargets[i]);
+    }
+    if (this.thumbnailUrl_)
+      break;
+  }
+
+  if (!this.thumbnailUrl_ && this.fallbackUrl_) {
     // Use fallback as the primary thumbnail.
     this.thumbnailUrl_ = this.fallbackUrl_;
     this.fallbackUrl_ = null;
@@ -95,13 +126,16 @@ ThumbnailLoader.LoaderType = {
 };
 
 /**
- * Whether to use the embedded thumbnail, or not. The embedded thumbnail may
- * be small.
- * @enum {number}
+ * Load target of ThumbnailLoader.
+ * @enum {string}
  */
-ThumbnailLoader.UseEmbedded = {
-  USE_EMBEDDED: 0,
-  NO_EMBEDDED: 1
+ThumbnailLoader.LoadTarget = {
+  // e.g. Drive thumbnail, FSP thumbnail.
+  EXTERNAL_METADATA: 'externalMetadata',
+  // e.g. EXIF thumbnail.
+  CONTENT_METADATA: 'contentMetadata',
+  // Image file itself.
+  FILE_ENTRY: 'fileEntry'
 };
 
 /**
@@ -119,13 +153,11 @@ ThumbnailLoader.THUMBNAIL_MAX_WIDTH = 500;
 ThumbnailLoader.THUMBNAIL_MAX_HEIGHT = 500;
 
 /**
- * Returns whether the metadata have the thumbnail information or not.
- * @param {!Object} metadata Metadata.
- * @return {boolean}
+ * Returns the target of loading.
+ * @return {?ThumbnailLoader.LoadTarget}
  */
-ThumbnailLoader.hasThumbnailInMetadata = function(metadata) {
-  return (metadata.thumbnail && metadata.thumbnail.url) ||
-      (metadata.external && metadata.external.thumbnailUrl);
+ThumbnailLoader.prototype.getLoadTarget = function() {
+  return this.loadTarget_;
 };
 
 /**