Fix a crash when download a DRM file through context menu

Fix a crash when download a DRM file through context menu

This is a regression introduced by
https://codereview.chromium.org/1717783002.
Previously we use URLUtil.guessFileName() to generate file names for
download.
However, to fix crbug/570750, we rely on the native code to pass the
file name.
However, drm download through context menu bypasses the native download
code.
As a result, we need to generate the file name in Java if it is null.
Since content disposition is null, this will not cause the same problem
as reported in crbug/570750.

TBR=tedchoc@chromium.org
BUG=608258
Review-Url: https://codereview.chromium.org/2013643002
Cr-Commit-Position: refs/heads/master@{#395750}
(cherry picked from commit 4e33c5d6978752f31ed6702e72e46fdf78cd5565)

Committed: https://chromium.googlesource.com/chromium/src/+/421b2fbe002d915307cc547e86b6004bba0bf4a3

[qinmin, 2016-05-26 18:39:17]

Description was changed from

==========
Fix a crash when download a DRM file through context menu

This is a regression introduced by
https://codereview.chromium.org/1717783002.
Previously we use URLUtil.guessFileName() to generate file names for
download.
However, to fix crbug/570750, we rely on the native code to pass the
file name.
However, drm download through context menu bypasses the native download
code.
As a result, we need to generate the file name in Java if it is null.
Since content disposition is null, this will not cause the same problem
as reported in crbug/570750.

TBR=tedchoc@chromium.org
BUG=608258

Review-Url: https://codereview.chromium.org/2013643002
Cr-Commit-Position: refs/heads/master@{#395750}
(cherry picked from commit 4e33c5d6978752f31ed6702e72e46fdf78cd5565)
==========

to

==========
Fix a crash when download a DRM file through context menu

This is a regression introduced by
https://codereview.chromium.org/1717783002.
Previously we use URLUtil.guessFileName() to generate file names for
download.
However, to fix crbug/570750, we rely on the native code to pass the
file name.
However, drm download through context menu bypasses the native download
code.
As a result, we need to generate the file name in Java if it is null.
Since content disposition is null, this will not cause the same problem
as reported in crbug/570750.

TBR=tedchoc@chromium.org
BUG=608258

Review-Url: https://codereview.chromium.org/2013643002
Cr-Commit-Position: refs/heads/master@{#395750}
(cherry picked from commit 4e33c5d6978752f31ed6702e72e46fdf78cd5565)

Committed:
https://chromium.googlesource.com/chromium/src/+/421b2fbe002d915307cc547e86b6...
==========

[qinmin, 2016-05-26 18:39:19]

Committed patchset #1 (id:1) manually as
421b2fbe002d915307cc547e86b6004bba0bf4a3 (presubmit successful).