Add thumbnailMetadataItem to GalleryItem.

Add thumbnailMetadataItem to GalleryItem.

Previously the thumbnail metadata is obtained as a part of old metadata.  The CL
adds thumbnailMetadataItem to GalleryItem, and remove old metadata models from
Gallery.

BUG=410766
TEST=None

Committed: https://crrev.com/cf5fff0e7fc1f67739c5624c3ef0619b7641ebb1
Cr-Commit-Position: refs/heads/master@{#319047}

[hirono, 2015-03-04 09:16:46]

hirono@chromium.org changed reviewers:
+ mtomasz@chromium.org

[hirono, 2015-03-04 09:16:47]

PTAL, thanks!

[mtomasz, 2015-03-04 09:29:59]

lgtm with some nits

https://codereview.chromium.org/976713004/diff/40001/ui/file_manager/gallery/...
File ui/file_manager/gallery/js/gallery.js (right):

https://codereview.chromium.org/976713004/diff/40001/ui/file_manager/gallery/...
ui/file_manager/gallery/js/gallery.js:262: ['imageWidth', 'imageHeight', 'size',
'present'];
nit: Why present is added?
nit: Is size used?

[hirono, 2015-03-04 10:00:35]

On 2015/03/04 09:29:59, mtomasz wrote:
> lgtm with some nits
> 
>
https://codereview.chromium.org/976713004/diff/40001/ui/file_manager/gallery/...
> File ui/file_manager/gallery/js/gallery.js (right):
> 
>
https://codereview.chromium.org/976713004/diff/40001/ui/file_manager/gallery/...
> ui/file_manager/gallery/js/gallery.js:262: ['imageWidth', 'imageHeight',
'size',
> 'present'];
> nit: Why present is added?
> nit: Is size used?

Thanks!

The 'present' and 'size' are used here.
https://code.google.com/p/chromium/codesearch#chromium/src/ui/file_manager/ga...
https://code.google.com/p/chromium/codesearch#chromium/src/ui/file_manager/ga...

[hirono, 2015-03-04 10:01:24]

The CQ bit was checked by hirono@chromium.org

[commit-bot: I haz the power, 2015-03-04 10:01:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/976713004/40001

[commit-bot: I haz the power, 2015-03-04 10:04:46]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-03-04 10:05:39]

Patchset 3 (id:??) landed as
https://crrev.com/cf5fff0e7fc1f67739c5624c3ef0619b7641ebb1
Cr-Commit-Position: refs/heads/master@{#319047}