Speculative revert to fix ChromeOS PFQ mips builder

Speculative revert to fix ChromeOS PFQ mips builder

The original change is suspected of breaking the build
and the second one is followup that needs to be reverted
along with it.

Revert "Fix use of 'sysroot' variable in harfbuzz.gyp"
https://codereview.chromium.org/1158283003

Revert "Fix common.gypi when run with target_arch=mips"
https://codereview.chromium.org/1166523004

TBR=cpu
BUG=496462
Committed: https://crrev.com/3f39737a0258d942440b9abe589f06c7305bfb77
Cr-Commit-Position: refs/heads/master@{#332766}

[Sam Clegg, 2015-06-04 00:57:18]

sbc@chromium.org changed reviewers:
+ jonross@chromium.org, matthewyuan@chromium.org

[jonross, 2015-06-04 01:36:35]

On 2015/06/04 00:57:18, Sam Clegg wrote:

LGTM

[Sam Clegg, 2015-06-04 02:07:33]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2015-06-04 02:08:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1159083004/1

[commit-bot: I haz the power, 2015-06-04 02:13:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-04 02:14:16]

Patchset 1 (id:??) landed as
https://crrev.com/3f39737a0258d942440b9abe589f06c7305bfb77
Cr-Commit-Position: refs/heads/master@{#332766}