Add 'import' and 'imageset' to WebURLRequest::RequestContext enum.

Add 'import' and 'imageset' to WebURLRequest::RequestContext enum.

BUG=390497
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179380

[Mike West, 2014-07-30 12:37:10]

Step 2; depends on https://codereview.chromium.org/428733010/ landing in
Chromium.

[jochen (gone - plz use gerrit), 2014-07-30 13:57:48]

lgtm

[Mike West, 2014-07-31 12:29:01]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2014-07-31 12:29:26]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mkwst@chromium.org/429213002/1

[commit-bot: I haz the power, 2014-07-31 13:45:25]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/1...)
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/17857)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/19861)

[commit-bot: I haz the power, 2014-07-31 14:15:02]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-07-31 14:15:03]

Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/1...)

[Mike West, 2014-08-01 06:13:50]

The CQ bit was checked by mkwst@chromium.org

[commit-bot: I haz the power, 2014-08-01 06:14:21]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mkwst@chromium.org/429213002/20001

[commit-bot: I haz the power, 2014-08-01 07:24:27]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/20052)

[commit-bot: I haz the power, 2014-08-01 08:29:11]

Change committed as 179380