clang: don't build unused function
clang: don't build unused function

This function is not used when the tested #define isn't available.

TEST=compiles

Review URL: http://codereview.chromium.org/3290001

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@59247 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