Build internals of Skia with c++17

Change-Id: I7fedc818b6fad5c08f37c8002268c65eefdf57a2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1757345
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713492}

skia/BUILD.gn

@@ -190,7 +190,11 @@ config("skia_library_config") {
                   # assembly code contains flow control(jmp or jcc) statements.
 
       "/wd4800",  # forcing value to bool 'true/false'(assigning int to bool).
+      "/wd5041",  # out-of-line definition for constexpr static data member is not needed and is deprecated in C++17
     ]
+    cflags_cc = [ "/std:c++17" ]
+  } else {
+    cflags_cc = [ "-std=c++17" ]
   }
 }