win: remove flags not present in chromium

Removed flags to disable warnings not present in
chromium/src/build/config/compiler/BUILD.gn

Change-Id: Id191e17c2d6c738c91a26c1c5bcd6ab5e306dd59
Reviewed-on: https://chromium-review.googlesource.com/942486
Reviewed-by: Mark Mentovai <mark@chromium.org>

build/BUILD.gn

diff --git a/build/BUILD.gn b/build/BUILD.gn
index a169315..56e33d8 100644
--- a/build/BUILD.gn
+++ b/build/BUILD.gn
@@ -143,12 +143,9 @@
       "/bigobj",  # Support larger number of sections in obj file.
       "/wd4100",  # Unreferenced formal parameter.
       "/wd4127",  # Conditional expression is constant.
-      "/wd4201",  # Nonstandard extension used: nameless struct/union.
       "/wd4324",  # Structure was padded due to alignment specifier.
       "/wd4351",  # New behavior: elements of array will be default initialized.
-      "/wd4530",  # Exceptions disabled.
       "/wd4577",  # 'noexcept' used with no exception handling mode specified.
-      "/wd4702",  # Unreachable code.
       "/wd4996",  # 'X' was declared deprecated.
     ]