Mark FastSharedBufferReader's methods const

Mark FastSharedBufferReader's methods const

The methods are logically const (besides setData, which was left
unchanged). The mutable fields are merely caches, to make subsequent
nearby accesses (which are likely) faster.

Make BMP methods using FastSharedBufferReader const.

BUG=439655
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=201839

[scroggo_chromium, 2015-09-04 21:46:52]

scroggo@chromium.org changed reviewers:
+ noel@chromium.org, pkasting@google.com

[scroggo_chromium, 2015-09-04 21:46:53]

This was brought up in a previous review [1]. As far as I can tell, making these
methods not const was not a deliberate decision (the CL that introduces them [2]
does not include const, and the reviews do not mention whether they should be).

[1]
https://codereview.chromium.org/1259083003/diff/60001/Source/platform/image-d...
[2] crrev.com/976153002

[Peter Kasting, 2015-09-04 22:49:42]

pkasting@chromium.org changed reviewers:
+ pkasting@chromium.org

[Peter Kasting, 2015-09-04 22:49:42]

LGTM

Any other caller methods that can now be made const?

[scroggo_chromium, 2015-09-04 22:58:03]

On 2015/09/04 22:49:42, Peter Kasting wrote:
> LGTM
> 
> Any other caller methods that can now be made const?

Not that I see. It looks like all of the callers (besides tests) are inside
GIFImageReader::parseData, which modifies lots of GIFImageReader variables.

[Noel Gordon, 2015-09-05 00:53:01]

LGTM

[Noel Gordon, 2015-09-05 01:03:53]

The CQ bit was checked by noel@chromium.org

[commit-bot: I haz the power, 2015-09-05 01:04:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1309363006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1309363006/1

[commit-bot: I haz the power, 2015-09-05 02:26:21]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=201839