linux: don't show deprecation warnings in third-party code
linux: don't show deprecation warnings in third-party code

When building e.g. the protocol compiler, don't show warnings
about using hash_map.  ffmpeg also has similar deprecated
API warnings.

Review URL: http://codereview.chromium.org/6462008

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@74187 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser