Reland r202508: Made the open menu item in the context menu updated when the context menu is open.

Reland r202508: Made the open menu item in the context menu updated when the context menu is open.

Original patch broke SelectFileAndOpen browser test. This is because Files.app
notify 'selection-change-complete' to the tests even if the selection is empty.
This CL is fixed the problem by adding a check of the number of selected items.

Previously reverted CL: crrev.com/15950003

BUG=243687
TEST=browser_tests

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=202798

[hirono, 2013-05-29 01:53:41]

@yoshiki-san,
crrev.com/15950003 was reverted.
Could you check the CL to reland this?

Thank you!

[hirono, 2013-05-29 01:54:14]

@yoshiki-san,
crrev.com/15950003 was reverted.
Could you check the CL to reland this?

Thank you!

[yoshiki, 2013-05-29 02:24:11]

lgtm

[commit-bot: I haz the power, 2013-05-29 02:24:42]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hirono@chromium.org/15808007/1

[commit-bot: I haz the power, 2013-05-29 02:55:18]

Step "update" is always a major failure.
Look at the try server FAQ for more details.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2013-05-29 03:32:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hirono@chromium.org/15808007/1

[commit-bot: I haz the power, 2013-05-29 07:44:01]

Change committed as 202798