Return if a host name in an URLPattern has no non-whitespace characters.

Return if a host name in an URLPattern has no non-whitespace characters.

SplitString trims whitespace, so the |host_components| vector could be empty.

BUG=390645
TEST=ExtensionURLPatternTest.ParseInvalid

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=280935

[Devlin, 2014-07-01 21:50:24]

LGTM

[robwu, 2014-07-01 21:59:21]

The CQ bit was checked by rob@robwu.nl

[commit-bot: I haz the power, 2014-07-01 22:00:11]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/rob@robwu.nl/364703002/1

[commit-bot: I haz the power, 2014-07-01 23:53:20]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)
  linux_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu_trigger...)

[commit-bot: I haz the power, 2014-07-02 01:32:00]

Change committed as 280935