~chromium-team/chromium-browser/artful-beta

* Upstream beta channel update: 66.0.3359.45
* debian/rules:
  - remove use_system_sqlite build flag
  - bootstrap the build (build gn) with clang
* debian/patches/configuration-directory.patch: refreshed
* debian/patches/default-allocator: refreshed
* debian/patches/disable-sse2: refreshed
* debian/patches/last-commit-position: refreshed
* debian/patches/revert-clang-nostdlib++.patch: refreshed
* debian/patches/revert-Xclang-instcombine-lower-dbg-declare.patch: refreshed
* debian/patches/search-credit.patch: refreshed
* debian/patches/set-rpath-on-chromium-executables.patch: refreshed
* debian/patches/suppress-newer-clang-warning-flags.patch: updated
* debian/patches/touch-v35: refreshed
* debian/patches/use-clang-versioned.patch: refreshed
* debian/patches/widevine-other-locations: refreshed
* debian/known_gn_gen_args-*: remove use_system_sqlite build flag