Revert of Implement DisplayList GatherPixelRefs

Revert of Implement DisplayList GatherPixelRefs (patchset #5 id:80001 of https://codereview.chromium.org/1045953002/)

Reason for revert:
Cause of crbug.com/472590

Original issue's description:
> Implement DisplayList GatherPixelRefs
>
> Take advantage of DisplayList playing back to generate SkPicture, and
> use existing functions that gathers pixel ref from a single SkPicture.
>
> R=ajuma, enne, vmpstr
> BUG=440468
>
> Committed: https://crrev.com/3d69b19b57904847ffec31b0f5d4f3568b5c6f35
> Cr-Commit-Position: refs/heads/master@{#323152}

TBR=enne@chromium.org,ajuma@chromium.org,vmpstr@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=440468
Committed: https://crrev.com/74cb97d8d5c4e62a694c7f029a7c8c0b09e5bd92
Cr-Commit-Position: refs/heads/master@{#323321}

[weiliangc, 2015-04-01 20:35:25]

Created Revert of Implement DisplayList GatherPixelRefs

[commit-bot: I haz the power, 2015-04-01 20:36:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1047413003/1

[weiliangc, 2015-04-01 20:37:27]

The CQ bit was unchecked by weiliangc@chromium.org

[commit-bot: I haz the power, 2015-04-01 20:37:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-01 20:38:44]

Patchset 1 (id:??) landed as
https://crrev.com/74cb97d8d5c4e62a694c7f029a7c8c0b09e5bd92
Cr-Commit-Position: refs/heads/master@{#323321}

[weiliangc, 2015-04-01 20:48:48]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1050103003/ by weiliangc@chromium.org.

The reason for reverting is: Break tree.