Revert of Never consolidate data in ICO decoder

Revert of Never consolidate data in ICO decoder (patchset #3 id:40001 of https://codereview.chromium.org/1316203008/ )

Reason for revert:
Causing crbug.com/530279. Will reland once I have fixed the problem.

Will next revert crrev.com/1259083003 (otherwise crbug.com/528625 will show back up).

I will reland both CLs together as one CL that fixes the problems.

Original issue's description:
> Never consolidate data in ICO decoder
> 
> Follows the same approach as BMPImageDecoder: Use a
> FastSharedBufferReader to avoid consolidation.
> 
> Add an optional offset to PNGImageDecoder for ICOImageDecoder, so that
> PNGImageDecoder can read a PNG subimage in an ICO without copying the
> data. This eliminates another call to SharedBuffer::data(), as well as
> a copy to create the separate SharedBuffer for PNG.
> 
> BUG=467772
> BUG=528625
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=201981

TBR=pkasting@chromium.org,noel@chromium.org,scroggo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=467772
Committed: https://crrev.com/05865c1b34b6c653b893b6f8bce7b86ddafadc4d
git-svn-id: svn://svn.chromium.org/blink/trunk@202198 bbb929c8-8fbe-4397-9dbb-9b2b20218538

[scroggo, 2015-09-14 13:27:25]

Created Revert of Never consolidate data in ICO decoder

[commit-bot: I haz the power, 2015-09-14 13:27:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338293002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338293002/1

[commit-bot: I haz the power, 2015-09-14 13:27:32]

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

[commit-bot: I haz the power, 2015-09-14 13:27:33]

No L-G-T-M from a valid reviewer yet. Only full committers are accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[Noel Gordon, 2015-09-14 13:34:58]

LGTM

[Noel Gordon, 2015-09-14 13:35:08]

The CQ bit was checked by noel@chromium.org

[commit-bot: I haz the power, 2015-09-14 13:35:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338293002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338293002/1

[commit-bot: I haz the power, 2015-09-14 13:35:36]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=202198

[Peter Kasting, 2015-09-14 19:43:26]

LGTM

[commit-bot: I haz the power, 2015-09-23 12:31:54]

Patchset 1 (id:??) landed as
https://crrev.com/05865c1b34b6c653b893b6f8bce7b86ddafadc4d