The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/20ec56f7a363fe573cfe99b2d50911a55b379f08

commit 20ec56f7a363fe573cfe99b2d50911a55b379f08
Author: prashant.n <prashant.n@samsung.com>
Date: Thu Sep 22 03:47:32 2016

cc: Implement IndexRect for encapsulating tile indices.

The tiling data has many occurrences of left, right, top, bottom
indices. Encapsulating them in an object will help reduce the number
of variables passed in function or used as members in class.

BUG= 624792 
TESTS=IndexRectTest.*
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel

Review-Url: https://codereview.chromium.org/2350563002
Cr-Commit-Position: refs/heads/master@{#420256}

[modify] https://crrev.com/20ec56f7a363fe573cfe99b2d50911a55b379f08/cc/BUILD.gn
[modify] https://crrev.com/20ec56f7a363fe573cfe99b2d50911a55b379f08/cc/base/BUILD.gn
[add] https://crrev.com/20ec56f7a363fe573cfe99b2d50911a55b379f08/cc/base/index_rect.cc
[add] https://crrev.com/20ec56f7a363fe573cfe99b2d50911a55b379f08/cc/base/index_rect.h
[add] https://crrev.com/20ec56f7a363fe573cfe99b2d50911a55b379f08/cc/base/index_rect_unittest.cc
[modify] https://crrev.com/20ec56f7a363fe573cfe99b2d50911a55b379f08/cc/base/tiling_data.cc
[modify] https://crrev.com/20ec56f7a363fe573cfe99b2d50911a55b379f08/cc/base/tiling_data.h