Pixel double the NTP background

As background-image doesn't have a notion of the size it is supposed to be, when the 2x version of the new tab background is requested and the request fails, the 1x version is shown but not pixel doubled.
This CL specifies explicitly that only the 1x version is available. 

BUG=141171, 133934
Test=Manual, instructions below
1) Run chrome with --force-device-scale-factor=2
2) Change the theme to "Kate Spade" from the Chromium web store.
3) Ensure that the bookmark bar is hidden
4) Create a new tab. Ensure that the stripes in the new tab page match up with those in the tabstrip

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=150744

[flackr, 2012-08-08 14:10:01]

lgtm, but I assume we'll need a way to conditionally support 2x theme
backgrounds if/when these are available.

[pkotwicz, 2012-08-08 14:16:55]

Nico can you take a look at this when you have time?

[Nico, 2012-08-08 14:21:26]

With this patch, the 2x variant is never requested, right? Does that impact
hidpi themes? If so, can you add 133934 to the BUG= line so that future you (or
whoever ends up doing hidpi themes) remembers to undo this?

Other than that, lgtm. Please wait for the LG from an NTP owner too. (I cc'd
dbeam.)

(In the global scheme of things, I'd say this is less important than the hidpi
favicon db tho ;-) )

[pkotwicz, 2012-08-08 17:33:30]

Yes, this patch has the effect that you have described. The 2x variant is never
requested.
It will affect hidpi themes once we implement support for hidpi themes.

[Dan Beam, 2012-08-08 17:56:57]

rs lgtm (not really familiar with this nor do I have a high DPI screen to verify
this work)

[commit-bot: I haz the power, 2012-08-08 18:37:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/10836139/1

[commit-bot: I haz the power, 2012-08-08 19:55:43]

Try job failure for 10836139-1 (retry) on linux_rel for step "media_unittests".
It's a second try, previously, step "media_unittests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2012-08-08 20:02:25]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/10836139/1

[commit-bot: I haz the power, 2012-08-08 22:49:46]

Try job failure for 10836139-1 (retry) on win_rel for step "browser_tests".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2012-08-09 01:06:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/10836139/1

[commit-bot: I haz the power, 2012-08-09 01:26:24]

Try job failure for 10836139-1 (retry) on win for step "runhooks".
It's a second try, previously, step "runhooks" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win&number...

[commit-bot: I haz the power, 2012-08-09 02:36:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/10836139/1

[commit-bot: I haz the power, 2012-08-09 05:30:59]

Change committed as 150744