DM: add --tileGrid

DM: add --tileGrid

BUG=
R=epoger@google.com

Committed: https://code.google.com/p/skia/source/detail?r=12408

[epoger, 2013-11-26 22:26:00]

LGTM if you make the following changes

(I'll be out until Dec 3, so if you make those changes, go ahead and commit)

https://codereview.chromium.org/88563003/diff/60001/dm/DMTileGridTask.cpp
File dm/DMTileGridTask.cpp (right):

https://codereview.chromium.org/88563003/diff/60001/dm/DMTileGridTask.cpp#new...
dm/DMTileGridTask.cpp:9: // Tile grid tests are currently failing.  (Skia issue
1198).  When fixed, default to true.
Maybe make this a TODO(mtklein) for searchability

https://codereview.chromium.org/88563003/diff/60001/dm/DMTileGridTask.cpp#new...
dm/DMTileGridTask.cpp:22: static int divide_round(int x, int y) {
Maybe add documentation and rename to make the operation clearer (because
"divide_round" doesn't really tell you what it does, unless you already know and
you just need your memory jogged)

/**
 * For a particular dimension (X or Y), figure out how many tiles
 * we need to hold the entire bitmap.
 */
static int tiles_needed(int bitmapDimension, int tileDimension) {
  return (bitmapDimension + tileDimension - 1) / tileDimension;
}

[mtklein, 2013-11-26 23:34:34]

Thanks Elliot.

https://codereview.chromium.org/88563003/diff/60001/dm/DMTileGridTask.cpp
File dm/DMTileGridTask.cpp (right):

https://codereview.chromium.org/88563003/diff/60001/dm/DMTileGridTask.cpp#new...
dm/DMTileGridTask.cpp:9: // Tile grid tests are currently failing.  (Skia issue
1198).  When fixed, default to true.
On 2013/11/26 22:26:01, epoger wrote:
> Maybe make this a TODO(mtklein) for searchability

Done.

https://codereview.chromium.org/88563003/diff/60001/dm/DMTileGridTask.cpp#new...
dm/DMTileGridTask.cpp:22: static int divide_round(int x, int y) {
On 2013/11/26 22:26:01, epoger wrote:
> Maybe add documentation and rename to make the operation clearer (because
> "divide_round" doesn't really tell you what it does, unless you already know
and
> you just need your memory jogged)
> 
> /**
>  * For a particular dimension (X or Y), figure out how many tiles
>  * we need to hold the entire bitmap.
>  */
> static int tiles_needed(int bitmapDimension, int tileDimension) {
>   return (bitmapDimension + tileDimension - 1) / tileDimension;
> }

Done.

[mtklein, 2013-11-26 23:36:55]

Committed patchset #5 manually as r12408 (presubmit successful).