Fix DownloadsDOMHandler::OnDownloadDestroyed

Fix DownloadsDOMHandler::OnDownloadDestroyed() to not set *vector::end() = NULL.
DownloadsDOMHandler::download_items_ does not always contain all of the items that it observes, so std::find may return end(). I have no idea what happens when you set *end()=NULL, but it could explain the crash in DownloadsDOMHandler::ClearDownloadItems() on windows, somewhere in "for (OrderedDownloads::iterator it = download_items_.begin(); it != download_items_.end(); ++it)".
BUG=142389
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=151395

[benjhayden, 2012-08-13 21:27:30]

PTAL

[Randy Smith (Not in Mondays), 2012-08-13 21:39:58]

LGTM.

[benjhayden, 2012-08-13 21:47:06]

Just need OWNERShip review from either James or Evan, then I'll hit the CQ and
it should land tonight.
Thanks!

[benjhayden, 2012-08-13 21:47:35]

+Karen

[James Hawkins, 2012-08-13 21:52:51]

Please provide a better CL description before committing.

LGTM

[commit-bot: I haz the power, 2012-08-13 22:01:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/benjhayden@chromium.org/10855135/1

[benjhayden, 2012-08-13 22:02:29]

On 2012/08/13 21:52:51, James Hawkins wrote:
> Please provide a better CL description before committing.
> 
> LGTM

Thanks!

I'll be afk for the next hour, but I'll check the cq every few minutes on my
walk home, and deal with any issues when I get home.

[commit-bot: I haz the power, 2012-08-13 23:30:26]

Try job failure for 10855135-1 (retry) on linux_rel for step
"interactive_ui_tests".
It's a second try, previously, step "interactive_ui_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...