cc: Add PictureLayerTilingSet to manage PictureLayerTiling

cc: Add PictureLayerTilingSet to manage PictureLayerTiling

PictureLayerTilingSet has multiple tilings at different content scales.
This should abstract managing the tilings from PictureLayerImpl.  The
layer can then ask the set to fill in a given (integer) rect at a given
content scale and then get back the set of tiles/rects/texture
coordinates to generate that set.  Using an integer rect allows textures
at different contents scales to fill a piece of geometry without cracks.

R=nduca@chromium.org
BUG=155209
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=169083

[enne (OOO), 2012-11-21 02:15:21]

This was getting large, so I thought I'd put it up for review.  Is this along
the lines of the abstraction that you were thinking about, Nat? (I know you
dislike iterators, but I still think it makes the most sense here.)

The biggest missing pieces from testing is thinking about the best way to fake
out tile manager and make tiles have resource ids.  (Maybe I just iterate
through and set them on tiles myself and ignore tile manager?)

Once I get that piece, I can add more testing for PictureLayerTilingSet and
invalidations on PictureLayerTiling.

[nduca, 2012-11-21 07:12:59]

The iterator makes sense, actually. I was concerned when we were considering
something ~= kd tree, but this doesn't need that, so it lgtm

[commit-bot: I haz the power, 2012-11-21 14:44:04]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/enne@chromium.org/11417111/1

[commit-bot: I haz the power, 2012-11-21 15:38:35]

Sorry for I got bad news for ya.
Compile failed with a clobber build on win_rel.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2012-11-21 17:05:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/enne@chromium.org/11417111/6004

[commit-bot: I haz the power, 2012-11-21 19:15:31]

Change committed as 169083