Gallery: Start to use new metadata model in Gallery.

ui/file_manager/gallery/js/mosaic_mode.js

 // Copyright 2014 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.
 
 /**
  * @param {!Element} container Content container.
  * @param {!ErrorBanner} errorBanner Error banner.
  * @param {!cr.ui.ArrayDataModel} dataModel Data model.
  * @param {!cr.ui.ListSelectionModel} selectionModel Selection model.
  * @param {!VolumeManager} volumeManager Volume manager.
@@ skipping 2077 matching lines @@
         // are loaded as soon as possible.
         2);
     if (!this.thumbnailPreloader_.getLoadTarget())
       this.thumbnailPreloader_ = null;
   }
 
   // Dimensions are always acquired from the metadata. For local files, it is
   // extracted from headers. For Drive files, it is received via the Drive API.
   // If the dimensions are not available, then the fallback dimensions will be
   // used (same as for the generic icon).
+  var metadataItem = this.getItem().getMetadataItem();
   var width;
   var height;
-  if (metadata.media && metadata.media.width) {
-    width = metadata.media.width;
-    height = metadata.media.height;
-  } else if (metadata.external && metadata.external.imageWidth &&
-             metadata.external.imageHeight) {
-    width = metadata.external.imageWidth;
-    height = metadata.external.imageHeight;
+  if (metadataItem.imageWidth && metadataItem.imageHeight) {
+    width = metadataItem.imageWidth;
+    height = metadataItem.imageHeight;
   } else {
     // No dimensions in metadata, then use the generic dimensions.
     width = Mosaic.Tile.GENERIC_ICON_SIZE;
     height = Mosaic.Tile.GENERIC_ICON_SIZE;
   }
 
   if (width > height) {
     if (width > Mosaic.Tile.MAX_CONTENT_SIZE) {
       height = Math.round(height * Mosaic.Tile.MAX_CONTENT_SIZE / width);
       width = Mosaic.Tile.MAX_CONTENT_SIZE;
@@ skipping 196 matching lines @@
   return new ImageRect(this.left_ - this.container_.scrollLeft, this.top_,
       this.width_, this.height_).inflate(-margin, -margin);
 };
 
 /**
  * @return {number} X coordinate of the tile center.
  */
 Mosaic.Tile.prototype.getCenterX = function() {
   return this.left_ + Math.round(this.width_ / 2);
 };