Fix official build due to 2x.pak reference

Fix official build due to 2x.pak reference

My Metro/HiDPI change (r133613) broke the official build. The problem was that I was referencing the new 2x pak files but they aren't created by default yet.

Fix was to mark the references as optional.

BUG=
TEST=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=133939

[robertshield, 2012-04-24 19:51:31]

LGTM, assuming the 'optional' thing works.

I didn't see a reference to it in 
http://code.google.com/searchframe#OAMlx_jo-ck/tools/build/scripts/common/arc...

but I might be looking in the wrong place.

[Michael Moss, 2012-04-24 20:10:43]

On 2012/04/24 19:51:31, robertshield wrote:
> LGTM, assuming the 'optional' thing works.

Hmmm, you might be right. I mentioned to sail that I added this for syzygy, but
they ended up not needing it because it was no longer optional, so I might have
never submitted the associated code changes. Hold off for a bit while I take a
look.

[sail, 2012-04-24 20:12:08]

On 2012/04/24 20:10:43, Michael Moss wrote:
> On 2012/04/24 19:51:31, robertshield wrote:
> > LGTM, assuming the 'optional' thing works.
> 
> Hmmm, you might be right. I mentioned to sail that I added this for syzygy,
but
> they ended up not needing it because it was no longer optional, so I might
have
> never submitted the associated code changes. Hold off for a bit while I take a
> look.

Sounds good. Thanks for looking into it.

[sail, 2012-04-24 23:01:11]

mmoss is still working on adding support for the optional keyword.
In the meantime I'm landing a change to simply remove references to the new
resource paks for now. (See https://chromiumcodereview.appspot.com/10207024/).

I've rebased this CL off of the other one. Once the optional keyword support is
added this CL can go in.

[Michael Moss, 2012-04-25 18:20:32]

LGTM