Format GN, isn't checked in third_party, so missed it the first time.

Bug: skia:9939
Change-Id: Ia02803f93a8b90fd8d03465226379b028add7f5e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/274046
Auto-Submit: Weston Tracey <westont@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>

third_party/dawn/BUILD.gn

@@ -653,5 +653,5 @@ static_library("libdawn_proc") {
   ]
   sources = get_target_outputs(":libdawn_proc_gen")
   sources += [ "${dawn_root}/src/include/dawn/dawn_proc.h" ]
-  cflags = ["-Wno-strict-prototypes"]
+  cflags = [ "-Wno-strict-prototypes" ]
 }