Fix an issue when parsing extension from file name with white spaces

Fix an issue when parsing extension from file name with white spaces

MimeTypeMap.getFileExtensionFromUrl() only works for encoded urls.
As a result, white space is not supported.
However, file name may contain white spaces.
This causes the method to return empty extensions.
Convert file name to encoded strings doesn't work directly.
For instance, URLEncoder.encode() converts white space to "+" instead of
"%20".
So this change just extract the extension from file name directly.

BUG=637917
Committed: https://crrev.com/23ad64c72dc2f116a7b73c2d6803f449ebba2553
Cr-Commit-Position: refs/heads/master@{#418130}

[qinmin, 2016-09-13 00:01:20]

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

[qinmin, 2016-09-13 00:01:20]

PTAL

[gone, 2016-09-13 00:15:23]

lgtm

[qinmin, 2016-09-13 00:19:42]

The CQ bit was checked by qinmin@chromium.org

[commit-bot: I haz the power, 2016-09-13 00:20:16]

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, 2016-09-13 01:18:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-13 01:20:29]

Description was changed from

==========
Fix an issue when parsing extension from file name with white spaces

MimeTypeMap.getFileExtensionFromUrl() only works for encoded urls.
As a result, white space is not supported.
However, file name may contain white spaces.
This causes the method to return empty extensions.
Convert file name to encoded strings doesn't work directly.
For instance, URLEncoder.encode() converts white space to "+" instead of
"%20".
So this change just extract the extension from file name directly.

BUG=637917
==========

to

==========
Fix an issue when parsing extension from file name with white spaces

MimeTypeMap.getFileExtensionFromUrl() only works for encoded urls.
As a result, white space is not supported.
However, file name may contain white spaces.
This causes the method to return empty extensions.
Convert file name to encoded strings doesn't work directly.
For instance, URLEncoder.encode() converts white space to "+" instead of
"%20".
So this change just extract the extension from file name directly.

BUG=637917

Committed: https://crrev.com/23ad64c72dc2f116a7b73c2d6803f449ebba2553
Cr-Commit-Position: refs/heads/master@{#418130}
==========

[commit-bot: I haz the power, 2016-09-13 01:20:30]

Patchset 1 (id:??) landed as
https://crrev.com/23ad64c72dc2f116a7b73c2d6803f449ebba2553
Cr-Commit-Position: refs/heads/master@{#418130}