Fix the issue while clicking on offline page donwload notification

Fix the issue while clicking on offline page donwload notification

When OfflinePageDownloadBridge is created, it will load all the
offline page items.
However, openItem() can get called before all page items are loaded.
This causes the native side unable to find the downloaded item.
As a result, nothing happens when user clicks offline page download
success notification.
This CL waits for all the page items to get loaded before calling
openItem().

BUG=640467
Committed: https://crrev.com/7b88754c9ab1470d9732cb1f2e0a8deb65c590c9
Cr-Commit-Position: refs/heads/master@{#414317}

[qinmin, 2016-08-25 00:15:50]

qinmin@chromium.org changed reviewers:
+ dfalcantara@chromium.org, fgorski@chromium.org

[qinmin, 2016-08-25 00:15:51]

PTAL

[gone, 2016-08-25 00:26:08]

lgtm

[fgorski, 2016-08-25 01:29:54]

lgtm

[qinmin, 2016-08-25 04:15:04]

The CQ bit was checked by qinmin@chromium.org

[qinmin, 2016-08-25 04:15:05]

The CQ bit was unchecked by qinmin@chromium.org

[qinmin, 2016-08-25 04:15:05]

The CQ bit was checked by qinmin@chromium.org

[commit-bot: I haz the power, 2016-08-25 04:15:22]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-25 05:28:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-08-25 05:30:43]

Description was changed from

==========
Fix the issue while clicking on offline page donwload notification

When OfflinePageDownloadBridge is created, it will load all the
offline page items.
However, openItem() can get called before all page items are loaded.
This causes the native side unable to find the downloaded item.
As a result, nothing happens when user clicks offline page download
success notification.
This CL waits for all the page items to get loaded before calling
openItem().

BUG=640467
==========

to

==========
Fix the issue while clicking on offline page donwload notification

When OfflinePageDownloadBridge is created, it will load all the
offline page items.
However, openItem() can get called before all page items are loaded.
This causes the native side unable to find the downloaded item.
As a result, nothing happens when user clicks offline page download
success notification.
This CL waits for all the page items to get loaded before calling
openItem().

BUG=640467

Committed: https://crrev.com/7b88754c9ab1470d9732cb1f2e0a8deb65c590c9
Cr-Commit-Position: refs/heads/master@{#414317}
==========

[commit-bot: I haz the power, 2016-08-25 05:30:44]

Patchset 1 (id:??) landed as
https://crrev.com/7b88754c9ab1470d9732cb1f2e0a8deb65c590c9
Cr-Commit-Position: refs/heads/master@{#414317}