Remove obsolete comment

The reference to new_port_policy.md is a remnant from when gn was
part of the Chromium repository. It doesn't apply to GN. (See e.g.
the zOS patch.)

Also, the doc no longer exists in the Chromium tree, its contents
got merged elsewhere in
https://chromium-review.googlesource.com/c/chromium/src/+/3906683

Change-Id: I1791cf81f05bf257ca031b5235e6492490ab6bd9
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/15680
Commit-Queue: Takuto Ikuta <tikuta@google.com>
Reviewed-by: Brett Wilson <brettw@google.com>
Reviewed-by: Takuto Ikuta <tikuta@google.com>

src/gn/args.cc

diff --git a/src/gn/args.cc b/src/gn/args.cc
index 3b765f8..5592d4a 100644
--- a/src/gn/args.cc
+++ b/src/gn/args.cc
@@ -333,8 +333,6 @@
 #else
 #error Unknown OS type.
 #endif
-  // NOTE: Adding a new port? Please follow
-  // https://chromium.googlesource.com/chromium/src/+/master/docs/new_port_policy.md
 
   // Host architecture.
   static const char kX86[] = "x86";

src/util/build_config.h

diff --git a/src/util/build_config.h b/src/util/build_config.h
index 139f97a..63ca16e 100644
--- a/src/util/build_config.h
+++ b/src/util/build_config.h
@@ -62,8 +62,6 @@
 #else
 #error Please add support for your platform in build_config.h
 #endif
-// NOTE: Adding a new port? Please follow
-// https://chromium.googlesource.com/chromium/src/+/master/docs/new_port_policy.md
 
 // For access to standard BSD features, use OS_BSD instead of a
 // more specific macro.