Revert of Chromium-side patch to rename "--dump-render-tree" to "--run-layout-test".

Revert of Chromium-side patch to rename "--dump-render-tree" to "--run-layout-test". (patchset #1 id:1 of https://codereview.chromium.org/899103002/)

Reason for revert:
Speculatively reverting to try to fix broken Mac 10.8 retina and Nexus 4 layout tests.

Original issue's description:
> Chromium-side patch to rename "--dump-render-tree" to "--run-layout-test".
>
> At this point, "--run-layout-test" is the flag that is actually functional, and using "--dump-render-tree" simply causes the "--run-layout-test" to be appended to the command line.
>
> A subsequent Blink patch will change the scripts in Blink to use "--run-layout-test" instead of "--dump-render-tree".
>
> BUG=453252
>
> Committed: https://crrev.com/7066b52aa7103b402dea27c64ec17d45c373a838
> Cr-Commit-Position: refs/heads/master@{#314664}

TBR=avi@chromium.org,paulmeyer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=453252
Committed: https://crrev.com/4d353255acdd6735c78ef15960203553f68ce26b
Cr-Commit-Position: refs/heads/master@{#314756}

[dcheng, 2015-02-05 04:43:20]

Created Revert of Chromium-side patch to rename "--dump-render-tree" to
"--run-layout-test".

[commit-bot: I haz the power, 2015-02-05 04:43:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/896403002/1

[commit-bot: I haz the power, 2015-02-05 04:44:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-05 04:45:33]

Patchset 1 (id:??) landed as
https://crrev.com/4d353255acdd6735c78ef15960203553f68ce26b
Cr-Commit-Position: refs/heads/master@{#314756}