cc: Move LayerRasterTileIterator to a separate file and make it a queue

cc: Move LayerRasterTileIterator to a separate file and make it a queue

This patch removes PictureLayerImpl::LayerRasterTileIterator, moves
it to a separate file, renames it to TilingSetRasterQueue, and
makes its functionality be more queue-like instead of iterator-like.

Also, this patch adds a PLI::CreateRasterQueue to get a raster queue
for the layer.

This hides a bit more details of PLTS from PLI and allows us in
the future to optimize or create other types of TilingSetRasterQueues.

BUG=433048
R=reveman, enne

Committed: https://crrev.com/bc22bb72cbb3fdef0216fb7eba164954cdfdd313
Cr-Commit-Position: refs/heads/master@{#307287}

[vmpstr, 2014-11-21 00:32:09]

PTAL. I'll run some performance numbers in the morning to verify that this
doesn't regress anything important. 

This is just moving LayerRasterTileIterator to be a Queue, but I would like turn
the eviction level iterator into a queue as well, and move the implementation
away from the layer (since it's really a tiling set queue, not a layer queue).

[vmpstr, 2014-11-25 17:40:01]

vmpstr@chromium.org changed reviewers:
+ e.hakkinen@partner.samsung.com

[vmpstr, 2014-11-25 17:40:01]

+e.hakkinen for review.

[USE eero AT chromium.org, 2014-11-27 13:09:19]

e.hakkinen@samsung.com changed reviewers:
+ e.hakkinen@samsung.com
- e.hakkinen@partner.samsung.com

[USE eero AT chromium.org, 2014-11-27 13:15:07]

lgtm (as non-owner)

[vmpstr, 2014-12-03 14:23:54]

reveman@, could you take a look as well?

[reveman, 2014-12-03 15:36:44]

lgtm

[vmpstr, 2014-12-05 23:56:16]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2014-12-05 23:57:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/742343002/20001

[commit-bot: I haz the power, 2014-12-06 01:45:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-12-06 01:45:04]

Try jobs failed on following builders:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[vmpstr, 2014-12-08 17:45:24]

The CQ bit was checked by vmpstr@chromium.org

[commit-bot: I haz the power, 2014-12-08 17:46:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/742343002/20001

[commit-bot: I haz the power, 2014-12-08 18:38:24]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-12-08 18:39:31]

Patchset 2 (id:??) landed as
https://crrev.com/bc22bb72cbb3fdef0216fb7eba164954cdfdd313
Cr-Commit-Position: refs/heads/master@{#307287}