Refactor gles2_cmd_decoder_unittest.cc into components.

Refactor gles2_cmd_decoder_unittest.cc into components.

gles2_cmd_decoder_unittest.cc has gotten too big and additional work is
causing build errors on Win64.

See CL https://codereview.chromium.org/262793002/ for example.

This change splits up gles2_cmd_decoder_unittest.cc into smaller logical
components.

BUG=369596
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=267951

[vmiura, 2014-05-02 19:35:36]

PTAL.

[piman, 2014-05-02 19:54:33]

+1, thanks for this!

LGTM

[jbauman, 2014-05-02 20:19:23]

lgtm

[Zhenyao Mo, 2014-05-02 20:20:34]

LGTM

[vmiura, 2014-05-02 20:57:26]

The CQ bit was checked by vmiura@chromium.org

[commit-bot: I haz the power, 2014-05-02 20:57:57]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/vmiura@chromium.org/268773006/1

[commit-bot: I haz the power, 2014-05-02 21:18:39]

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

[commit-bot: I haz the power, 2014-05-02 21:18:40]

Try jobs failed on following builders:
  mac_chromium_rel on tryserver.chromium

[vmiura, 2014-05-02 21:19:14]

The CQ bit was checked by vmiura@chromium.org

[commit-bot: I haz the power, 2014-05-02 21:19:59]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/vmiura@chromium.org/268773006/1

[commit-bot: I haz the power, 2014-05-02 23:04:43]

Change committed as 267951