Quickfix for unknown warning in Chromium

Chromium uses clang 13.0 that likely removes the warning while Skia uses
clang 12.0 that still has the warning. Temporarily skip the
-Wno-return-std-move-in-c++11 in Chromium only while Skia changes to not
add warnings to it's third_party dependencies.

Bug: dawn:706
Change-Id: I625f0046204328dcf2cfb1eb9824f8a4a928b8ff
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/45240
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>

src/BUILD.gn

@@ -28,7 +28,7 @@ config("tint_common_config") {
     "${tint_spirv_tools_dir}/include",
   ]
 
-  if (is_clang) {
+  if (is_clang && !build_with_chromium) {
     # Suppress a warning enabled by Skia: Tint is C++14 so the C++11 defect
     # detected by this warning has been fixed.
     cflags = [ "-Wno-return-std-move-in-c++11" ]