[CleanUp] Remove parameter |by_user| in NotificationClosed

[CleanUp] Remove parameter |by_user| in NotificationClosed

As the comment in page_notification_delegate.cc by peter@,
Remove parameter |by_user| in function NotificationClosed.

BUG=
R=peter@chromium.org, jochen@chromium.org

Committed: https://crrev.com/dddf7dfdd489bea6d8d952c0981957b9c36b3926
Cr-Commit-Position: refs/heads/master@{#320433}

[zhuoyu.qian, 2015-03-12 02:07:42]

Hi Peter:
I'd like you to take a look at:
  chrome/browser/notifications/*

Hi jochen:
I'd like you to take a look at:
  content/public/browser/desktop_notification_delegate.h
  content/shell/browser/layout_test/layout_test_notification_manager.cc

[Peter Beverloo, 2015-03-12 02:17:29]

heh, cool. lgtm

Extensions do still expose this to developers, so we can't do cleanups higher up
the stack. Please run some try-bots to make sure that nothing breaks.

[zhuoyu.qian, 2015-03-12 02:19:57]

On 2015/03/12 02:17:29, Peter Beverloo wrote:
> heh, cool. lgtm
> 
> Extensions do still expose this to developers, so we can't do cleanups higher
up
> the stack. Please run some try-bots to make sure that nothing breaks.

For I don't have the right to do the try jobs, Could you please help me to run
the try-bos?
Thank you.

[Peter Beverloo, 2015-03-12 02:21:37]

On 2015/03/12 02:19:57, zhuoyu.qian wrote:
> On 2015/03/12 02:17:29, Peter Beverloo wrote:
> > heh, cool. lgtm
> > 
> > Extensions do still expose this to developers, so we can't do cleanups
higher
> up
> > the stack. Please run some try-bots to make sure that nothing breaks.
> 
> For I don't have the right to do the try jobs, Could you please help me to run
> the try-bos?
> Thank you.

Sure, I launched a bunch.

[jochen (gone - plz use gerrit), 2015-03-12 15:08:59]

lgtm

[zhuoyu.qian, 2015-03-13 01:04:46]

The CQ bit was checked by zhuoyu.qian@samsung.com

[commit-bot: I haz the power, 2015-03-13 01:05:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/993343006/1

[commit-bot: I haz the power, 2015-03-13 02:11:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-13 02:12:23]

Patchset 1 (id:??) landed as
https://crrev.com/dddf7dfdd489bea6d8d952c0981957b9c36b3926
Cr-Commit-Position: refs/heads/master@{#320433}