installer/linux: add symbolic icon for use in gnome-shell

chrome/installer/linux/common/installer.include

 # Recursively replace @@include@@ template variables with the referenced file,
 # and write the resulting text to stdout.
 process_template_includes() {
   INCSTACK+="$1->"
   # Includes are relative to the file that does the include.
   INCDIR=$(dirname $1)
   # Clear IFS so 'read' doesn't trim whitespace
   local OLDIFS="$IFS"
   IFS=''
   while read -r LINE
@@ skipping 218 matching lines @@
   if [ ! -f "${STAGEDIR}/${INSTALLDIR}/google-chrome" ]; then
     ln -sn "${INSTALLDIR}/${PACKAGE}" \
       "${STAGEDIR}/${INSTALLDIR}/google-chrome"
   fi
   ln -snf "${INSTALLDIR}/${PACKAGE}" \
     "${STAGEDIR}/usr/bin/${USR_BIN_SYMLINK_NAME}"
 
   # app icons
   install -m 644 \
     "${BUILDDIR}/installer/theme/product_logo_"*.png \
+    "${BUILDDIR}/installer/theme/product_symbolic_logo_"*.symbolic.png \
     "${BUILDDIR}/installer/theme/product_logo_32.xpm" \
     "${STAGEDIR}/${INSTALLDIR}/"
 
   # desktop integration
   install -m 755 "${BUILDDIR}/xdg-mime" "${STAGEDIR}${INSTALLDIR}/"
   install -m 755 "${BUILDDIR}/xdg-settings" "${STAGEDIR}${INSTALLDIR}/"
   process_template "${BUILDDIR}/installer/common/desktop.template" \
     "${STAGEDIR}/usr/share/applications/${PACKAGE}.desktop"
   chmod 644 "${STAGEDIR}/usr/share/applications/${PACKAGE}.desktop"
   process_template "${BUILDDIR}/installer/common/default-app.template" \
     "${STAGEDIR}/usr/share/gnome-control-center/default-apps/${PACKAGE}.xml"
   chmod 644 "${STAGEDIR}/usr/share/gnome-control-center/default-apps/${PACKAGE}.xml"
   process_template "${BUILDDIR}/installer/common/default-app-block.template" \
     "${STAGEDIR}${INSTALLDIR}/default-app-block"
   chmod 644 "${STAGEDIR}${INSTALLDIR}/default-app-block"
 
   # documentation
   install -m 755 "${BUILDDIR}/${PROGNAME}.1" \
     "${STAGEDIR}/usr/share/man/man1/${PACKAGE}.1"
 }