Add -Wsign-compare for C++ compilation on linux & friends. g++ -Wall includes -Wsign-compare on C++ source, but clang++ doesn't.
Add -Wsign-compare for C++ compilation on linux & friends.
g++ -Wall includes -Wsign-compare on C++ source, but clang++ doesn't.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6771022

git-svn-id: http://src.chromium.org/svn/trunk/src@79846 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 59e375fdcac222ed858554b1fd5e8de87294c874
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser