chromium: Stop setting clang_{base_path,use_chrome_plugins} in gn-utils.inc
chromium: Stop setting clang_{base_path,use_chrome_plugins} in gn-utils.inc

These variables always have the same values regardless of the toolchain used
by a target, so they can be set in GN_ARGS directly (just like they already
are).

Signed-off-by: Raphael Kubo da Costa <5fe4d20cf6ab8a2cf4e5e71d4c2d58346e96df0d@intel.com>

schnitzeltony/meta-browser,schnitzeltony/meta-browser,webdino/meta-browser,webdino/meta-browser,webdino/meta-browser,OSSystems/meta-browser,webdino/meta-browser,OSSystems/meta-browser,schnitzeltony/meta-browser,OSSystems/meta-browser,schnitzeltony/meta-browser,OSSystems/meta-browser,webdino/meta-browser