DevTools: do not show "there are unsaved changes" dialog for network resources

DevTools: do not show "there are unsaved changes" dialog for network resources

DevTools shows "there are unsaved changes" dialog if there's at least one
dirty uiSourceCode. However, saving a network-originated javascript file will
not prevent you from loosing changes as the devtools will close.

This patch changes the behavior so that the alerting message pops up only
if there are file system uiSourceCodes with unsaved changes.

R=vsevik
BUG=426783
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184856

[lushnikov, 2014-11-04 06:12:00]

ptal

[vsevik, 2014-11-05 07:35:13]

vsevik@chromium.org changed reviewers:
+ pfeldman@chromium.org

[vsevik, 2014-11-05 07:35:24]

lgtm

[vsevik, 2014-11-05 07:35:28]

The CQ bit was checked by vsevik@chromium.org

[vsevik, 2014-11-05 07:35:52]

The CQ bit was checked by vsevik@chromium.org

[commit-bot: I haz the power, 2014-11-05 07:36:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/698053003/1

[commit-bot: I haz the power, 2014-11-05 08:40:47]

Committed patchset #1 (id:1) as 184856