[Merge to 49] [Downloads] Avoid resetting SecureHash state across an interruption.

[Merge to 49] [Downloads] Avoid resetting SecureHash state across an interruption.

DownloadFileImpl/BaseFile was causing the SecureHash object to be
finalized when a download was interrupted. This caused the hash state to
be incorrect and subsequently the hash resulting from resuming the
download was also incorrect.

BUG=7648
BUG=581164
Review URL: https://codereview.chromium.org/1591523002

Cr-Commit-Position: refs/heads/master@{#371428}
(cherry picked from commit bdc7250e539a9f40f84fd157bc29481e5aac2bf8)

Committed: https://chromium.googlesource.com/chromium/src/+/662aed60b889672f028f1c4b8a357d7f36348efd

[asanka, 2016-01-28 15:30:46]

Description was changed from

==========
[Merge to 49] [Downloads] Avoid resetting SecureHash state across an
interruption.

DownloadFileImpl/BaseFile was causing the SecureHash object to be
finalized when a download was interrupted. This caused the hash state to
be incorrect and subsequently the hash resulting from resuming the
download was also incorrect.

BUG=7648
BUG=581164

Review URL: https://codereview.chromium.org/1591523002

Cr-Commit-Position: refs/heads/master@{#371428}
(cherry picked from commit bdc7250e539a9f40f84fd157bc29481e5aac2bf8)
==========

to

==========
[Merge to 49] [Downloads] Avoid resetting SecureHash state across an
interruption.

DownloadFileImpl/BaseFile was causing the SecureHash object to be
finalized when a download was interrupted. This caused the hash state to
be incorrect and subsequently the hash resulting from resuming the
download was also incorrect.

BUG=7648
BUG=581164

Review URL: https://codereview.chromium.org/1591523002

Cr-Commit-Position: refs/heads/master@{#371428}
(cherry picked from commit bdc7250e539a9f40f84fd157bc29481e5aac2bf8)

Committed:
https://chromium.googlesource.com/chromium/src/+/662aed60b889672f028f1c4b8a35...
==========

[asanka, 2016-01-28 15:30:47]

Committed patchset #1 (id:1) manually as
662aed60b889672f028f1c4b8a357d7f36348efd.