I have not changed any ".gyp" file.
I am using the following configuration to build.
export LDFLAGS="-Wl,--rpath-link,/usr/share/custom-toolchain/lib -Wl,--dynamic-linker,/usr/share/custom-toolchain/lib/ld-linux.so.2"
export CC=custom-gcc
export CCC=custom-gcc
export CXX=custom-g++
export NM=custom-nm
export RANLIB=custom-ranlib
export AR=custom-ar
export STRIP=custom-strip
export OBJDUMP=custom-objdump
export ADDR2LINE=custom-addr2line
export CPP=custom-cpp
export LD=custom-ld
export OBJCOPY=custom-objcopy
export READELF=custom-readelf
export SIZE=custom-size
export STRINGS=custom-strings
export PKG_CONFIG_PATH="/usr/share/custom-toolchain/lib/pkgconfig"
export PATH="/usr/share/custom-toolchain/bin":$PATH
myconf="-Dwerror= -Duse_openssl=1 -Duse_system_ffmpeg=0 -Dbuild_ffmpegsumo=1 -Dproprietary_codecs=1 -Dremove_webcore_debug_symbols=1
-Dlogging_like_official_build=1 -Ddisable_sse2=1 -Dsafe_browsing=0 -Dinput_speech=0 -Denable_google_now=0 -Denable_printing=0
-Denable_plugin_installation=0 -Duse_gnome_keyring=0 -Ddisable_nacl=1 -Ddisable_pnacl=1 -Duse_gconf=0 -Duse_gio=0
-Denable_hangout_services_extension=0 -Denable_wifi_bootstrapping=0 -Duse_pulseaudio=0 -Dlinux_link_libpci=0 -Duse_system_libexif=0 -Duse_kerberos=0"
./build/gyp_chromium build/all.gyp --depth . $myconf
../ninja-1.5.1/ninja -C out/Release chrome