[Merge M50] [Downloads] Retain a BlobDataHandle in DownloadUrlParameters.

[Merge M50] [Downloads] Retain a BlobDataHandle in DownloadUrlParameters.

This allows a caller to extend the lifetime of a blob until the
downloads / resource loader subsystems take over. Without this, an
unfortunately timed revokeObjectURL() call from the originating page may
invalidate the URL before the download has a chance to start the
associated download request.

BUG=595305
Review URL: https://codereview.chromium.org/1829413002

Cr-Commit-Position: refs/heads/master@{#383370}
(cherry picked from commit 6150c52a037d3b05eeac0faaf792ab0203b5580f)

Committed: https://chromium.googlesource.com/chromium/src/+/58242aeb11363fe0436724aefdc56faaf53321e4

[asanka, 2016-03-28 15:40:43]

Description was changed from

==========
[Merge M50] [Downloads] Retain a BlobDataHandle in DownloadUrlParameters.

This allows a caller to extend the lifetime of a blob until the
downloads / resource loader subsystems take over. Without this, an
unfortunately timed revokeObjectURL() call from the originating page may
invalidate the URL before the download has a chance to start the
associated download request.

BUG=595305

Review URL: https://codereview.chromium.org/1829413002

Cr-Commit-Position: refs/heads/master@{#383370}
(cherry picked from commit 6150c52a037d3b05eeac0faaf792ab0203b5580f)
==========

to

==========
[Merge M50] [Downloads] Retain a BlobDataHandle in DownloadUrlParameters.

This allows a caller to extend the lifetime of a blob until the
downloads / resource loader subsystems take over. Without this, an
unfortunately timed revokeObjectURL() call from the originating page may
invalidate the URL before the download has a chance to start the
associated download request.

BUG=595305

Review URL: https://codereview.chromium.org/1829413002

Cr-Commit-Position: refs/heads/master@{#383370}
(cherry picked from commit 6150c52a037d3b05eeac0faaf792ab0203b5580f)

Committed:
https://chromium.googlesource.com/chromium/src/+/58242aeb11363fe0436724aefdc5...
==========

[asanka, 2016-03-28 15:40:45]

Committed patchset #1 (id:1) manually as
58242aeb11363fe0436724aefdc56faaf53321e4.