Revert of Adding target to build SwiftShader

Revert of Adding target to build SwiftShader (patchset #4 id:60001 of https://codereview.chromium.org/2330173002/ )

Reason for revert:
This seems to not build in our sysroot: https://build.chromium.org/p/chromium.fyi/builders/ClangToTLinuxASan/builds/5244/steps/compile/logs/stdio

Original issue's description:
> Adding target to build SwiftShader
>
> Added the swiftshader target to BUILD.gn's deps in order to enable building SwiftShader using 'ninja -C out/Default swiftshader' or similar command. The 'swiftshader' target already existed in third_party/swiftshader/BUILD.gn, but was unaccessible due to not being referenced in any other BUILD.gn files. Note that SwiftShader does not automatically build with Chromium.
>
> BUG=630728
>
> Committed: https://crrev.com/72ce608cb69854a0029f019e67ddf1509c274f0a
> Cr-Commit-Position: refs/heads/master@{#418934}

TBR=sugoi@google.com,sugoi@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=630728
Committed: https://crrev.com/6e282042a9921e3f937e3e6d9e78b523d36b38c6
Cr-Commit-Position: refs/heads/master@{#419011}

[Nico, 2016-09-15 22:14:19]

The CQ bit was checked by thakis@chromium.org

[Nico, 2016-09-15 22:14:20]

Created Revert of Adding target to build SwiftShader

[commit-bot: I haz the power, 2016-09-15 22:14:58]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-15 22:15:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-15 22:17:47]

Description was changed from

==========
Revert of Adding target to build SwiftShader (patchset #4 id:60001 of
https://codereview.chromium.org/2330173002/ )

Reason for revert:
This seems to not build in our sysroot:
https://build.chromium.org/p/chromium.fyi/builders/ClangToTLinuxASan/builds/5...

Original issue's description:
> Adding target to build SwiftShader
> 
> Added the swiftshader target to BUILD.gn's deps in order to enable building
SwiftShader using 'ninja -C out/Default swiftshader' or similar command. The
'swiftshader' target already existed in third_party/swiftshader/BUILD.gn, but
was unaccessible due to not being referenced in any other BUILD.gn files. Note
that SwiftShader does not automatically build with Chromium.
> 
> BUG=630728
> 
> Committed: https://crrev.com/72ce608cb69854a0029f019e67ddf1509c274f0a
> Cr-Commit-Position: refs/heads/master@{#418934}

TBR=sugoi@google.com,sugoi@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=630728
==========

to

==========
Revert of Adding target to build SwiftShader (patchset #4 id:60001 of
https://codereview.chromium.org/2330173002/ )

Reason for revert:
This seems to not build in our sysroot:
https://build.chromium.org/p/chromium.fyi/builders/ClangToTLinuxASan/builds/5...

Original issue's description:
> Adding target to build SwiftShader
>
> Added the swiftshader target to BUILD.gn's deps in order to enable building
SwiftShader using 'ninja -C out/Default swiftshader' or similar command. The
'swiftshader' target already existed in third_party/swiftshader/BUILD.gn, but
was unaccessible due to not being referenced in any other BUILD.gn files. Note
that SwiftShader does not automatically build with Chromium.
>
> BUG=630728
>
> Committed: https://crrev.com/72ce608cb69854a0029f019e67ddf1509c274f0a
> Cr-Commit-Position: refs/heads/master@{#418934}

TBR=sugoi@google.com,sugoi@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=630728

Committed: https://crrev.com/6e282042a9921e3f937e3e6d9e78b523d36b38c6
Cr-Commit-Position: refs/heads/master@{#419011}
==========

[commit-bot: I haz the power, 2016-09-15 22:17:49]

Patchset 1 (id:??) landed as
https://crrev.com/6e282042a9921e3f937e3e6d9e78b523d36b38c6
Cr-Commit-Position: refs/heads/master@{#419011}