Gallery: Add items to GalleryDataModel before loading their metadata.

Gallery: Add items to GalleryDataModel before loading their metadata.

Previously Gallery adds image items to its model after fetching the
metadata. Because items are added by chunk, users cannot see all the items
before load completes. It causes strange behavior e.g. users may move from the
last item of the current chunk to the first item when the next chunk has not
been loaded.

The CL lets Gallery add all items to the model without fetching metadata. And
then, lets Gallery dispatch 'content' event to update thumbnails after fetching
metadata.

BUG=chrome-os-partner:33931
TEST=manually

Committed: https://crrev.com/0552d1680db5318d9e16708678a284037a19e4b8
Cr-Commit-Position: refs/heads/master@{#323898}

[hirono, 2015-04-06 06:36:22]

Patchset #1 (id:1) has been deleted

[hirono, 2015-04-06 06:36:31]

Patchset #1 (id:1) has been deleted

[hirono, 2015-04-06 07:30:05]

Patchset #1 (id:20001) has been deleted

[hirono, 2015-04-06 07:30:21]

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

[hirono, 2015-04-06 07:30:22]

PTAL, thanks!

[yoshiki, 2015-04-06 07:40:38]

lgtm with nit

https://codereview.chromium.org/853653004/diff/40001/ui/file_manager/gallery/...
File ui/file_manager/gallery/js/ribbon.js (right):

https://codereview.chromium.org/853653004/diff/40001/ui/file_manager/gallery/...
ui/file_manager/gallery/js/ribbon.js:180: element.style.marginLeft = '0';
nit: Should we apply a class, instead of assigning the style value directly?

[hirono, 2015-04-06 07:48:08]

Thanks!

https://codereview.chromium.org/853653004/diff/40001/ui/file_manager/gallery/...
File ui/file_manager/gallery/js/ribbon.js (right):

https://codereview.chromium.org/853653004/diff/40001/ui/file_manager/gallery/...
ui/file_manager/gallery/js/ribbon.js:180: element.style.marginLeft = '0';
On 2015/04/06 07:40:38, yoshiki wrote:
> nit: Should we apply a class, instead of assigning the style value directly? 

Yes! Done

[hirono, 2015-04-06 07:48:12]

The CQ bit was checked by hirono@chromium.org

[hirono, 2015-04-06 07:48:13]

The patchset sent to the CQ was uploaded after l-g-t-m from yoshiki@chromium.org
Link to the patchset: https://codereview.chromium.org/853653004/#ps60001 (title:
"Fixed.")

[commit-bot: I haz the power, 2015-04-06 07:48:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/853653004/60001

[commit-bot: I haz the power, 2015-04-06 08:17:08]

Committed patchset #2 (id:60001)

[commit-bot: I haz the power, 2015-04-06 08:18:02]

Patchset 2 (id:??) landed as
https://crrev.com/0552d1680db5318d9e16708678a284037a19e4b8
Cr-Commit-Position: refs/heads/master@{#323898}