drive: Discard upload location when there is no uploaded contents

drive: Discard upload location when GetUploadStatus fails
    
GetUploadStatus for an unusable URL always results in an error.
Upload location should be discarded to initiate new upload in such cases.

BUG=267452
R=kinaba@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=215801

[hashimoto, 2013-08-02 09:57:52]

kinaba@ please review.
tzik@ jfyi

[kinaba, 2013-08-02 10:36:59]

lgtm

[hashimoto, 2013-08-05 04:36:22]

Changed the approach to discard the upload location when GetUploadStatus()
fails.
PTAL

[hashimoto, 2013-08-06 01:30:53]

Patch Set 2 did not pay attention for non-resume case and always discarded the
upload location...
Fixed.
PTAL

[kinaba, 2013-08-06 01:42:38]

lgtm

[commit-bot: I haz the power, 2013-08-06 01:48:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hashimoto@chromium.org/21790002/31001

[commit-bot: I haz the power, 2013-08-06 02:40:26]

Retried try job too often on linux_rel for step(s) unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2013-08-06 03:05:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hashimoto@chromium.org/21790002/31001

[hashimoto, 2013-08-06 03:20:26]

Oops, the test is broken.
Fixed, PTAL.

[kinaba, 2013-08-06 03:21:41]

lgtm

[commit-bot: I haz the power, 2013-08-06 04:06:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hashimoto@chromium.org/21790002/56001

[hashimoto, 2013-08-06 05:44:57]

Committed patchset #4 manually as r215801 (presubmit successful).