Remove the compiler option _SILENCE_ALL_CXX17_DEPRECATION_WARNINGS

This patch removes the option _SILENCE_ALL_CXX17_DEPRECATION_WARNINGS
as now it is not needed.

Bug: dawn:824
Change-Id: I8e8e3b1d42350ea756f323767fa1201e999a8663
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/165240
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
diff --git a/src/dawn/common/BUILD.gn b/src/dawn/common/BUILD.gn
index 48c12fe..775fde7 100644
--- a/src/dawn/common/BUILD.gn
+++ b/src/dawn/common/BUILD.gn
@@ -184,10 +184,6 @@
     # (otherwise we have to add default: DAWN_UNREACHABLE() that silences clang too)
     cflags += [ "/wd4715" ]
 
-    # MSVC emits warnings when using constructs deprecated in C++17. Silence
-    # them until they are fixed.
-    # TODO(dawn:824): Fix all uses of C++ features deprecated in C++17.
-    defines += [ "_SILENCE_ALL_CXX17_DEPRECATION_WARNINGS" ]
     if (dawn_is_winuwp) {
       # /ZW makes sure we don't add calls that are forbidden in UWP.
       # and /EHsc is required to be used in combination with it,