MIPS: Resolve chromium and android webview build conflicts.
The mips related gyp variables and compiler flags for webview
and chromium builds are set externally. The CL ensures this
behaviour and prevents conflicts in configuration with standalone builds.
TEST=
BUG=
R=jkummerow@chromium.org, paul.lind@imgtec.com
Review URL: https://codereview.chromium.org/
707883002
Cr-Commit-Position: refs/heads/master@{#25243}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25243
ce2b1a6d-e550-0410-aec6-
3dcde31c8c00