Fix a crash caused by missing download ID from system DownloadManager for OMA downloads

Fix a crash caused by missing download ID from system DownloadManager for OMA downloads

When chrome crashes while OMA download is in progress, chrome will clear the download infomation when it restarts.
However, it is possible that the system download Id no longer exists in DownloadManager.
This will cause Chrome to crash on the first start up.
This CL catches the problem so we don't crash in this rare cases.

BUG=684100
Review-Url: https://codereview.chromium.org/2652863002
Cr-Commit-Position: refs/heads/master@{#445544}
Committed: https://chromium.googlesource.com/chromium/src/+/3482758e2164874b6d52e320e354da289b1c2c47

[qinmin, 2017-01-23 22:48:10]

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

[qinmin, 2017-01-23 22:48:11]

PTAL

[gone, 2017-01-23 22:49:12]

lgtm

[qinmin, 2017-01-23 22:54:55]

The CQ bit was checked by qinmin@chromium.org

[commit-bot: I haz the power, 2017-01-23 22:55:28]

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, 2017-01-23 23:36:11]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1485212095394730, "parent_rev":
"d0f86e5202cf482e5f6f1f802169ec05225e5d8e", "commit_rev":
"3482758e2164874b6d52e320e354da289b1c2c47"}

[commit-bot: I haz the power, 2017-01-23 23:36:49]

Description was changed from

==========
Fix a crash caused by missing download ID from system DownloadManager for OMA
downloads

When chrome crashes while OMA download is in progress, chrome will clear the
download infomation when it restarts.
However, it is possible that the system download Id no longer exists in
DownloadManager.
This will cause Chrome to crash on the first start up.
This CL catches the problem so we don't crash in this rare cases.

BUG=684100
==========

to

==========
Fix a crash caused by missing download ID from system DownloadManager for OMA
downloads

When chrome crashes while OMA download is in progress, chrome will clear the
download infomation when it restarts.
However, it is possible that the system download Id no longer exists in
DownloadManager.
This will cause Chrome to crash on the first start up.
This CL catches the problem so we don't crash in this rare cases.

BUG=684100

Review-Url: https://codereview.chromium.org/2652863002
Cr-Commit-Position: refs/heads/master@{#445544}
Committed:
https://chromium.googlesource.com/chromium/src/+/3482758e2164874b6d52e320e354...
==========

[commit-bot: I haz the power, 2017-01-23 23:36:51]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/3482758e2164874b6d52e320e354...