Merge "floss: Add compilation flags for libchrome"

defines += cxx=\"clang++\"

defines += cc=\"clang\"

defines += ar=\"ar\"

defines += external_cxxflags=[\"-I/usr/src/googletest/googletest/include\", \"-I/usr/src/googletest/googlemock/include\"]

defines += external_cxxflags=[\"-DNDEBUG\", \"-I/usr/src/googletest/googletest/include\", \"-I/usr/src/googletest/googlemock/include\", \"-Wno-unknown-warning-option\", \"-Wno-unused-command-line-argument\"]

defines += external_ldflags=[\"-latomic\", \"-labsl_base\", \"-labsl_bad_variant_access\"]

defines += enable_werror=false

defines += libdir=\"/usr/lib\"