Remove over-broad -Wheader-hygiene cflag (flutter#328)

GaryQian · web-flow · commit 64a121882eb5 · 2019-10-18T15:47:07.000-07:00
diff --git a/build/config/clang/BUILD.gn b/build/config/clang/BUILD.gn
@@ -9,8 +9,6 @@ import("clang.gni")
 # compile with these so may want to remove this config.
 config("extra_warnings") {
   cflags = [
-    "-Wheader-hygiene",
-
     # Warns when a const char[] is converted to bool.
     "-Wstring-conversion",
 
