Make *some* version of the Win GN build work.

R=scottmg@chromium.org, brettw@chromium.org
BUG=354261

Review URL: https://codereview.chromium.org/709593004

Cr-Original-Commit-Position: refs/heads/master@{#303366}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 43760591658239084cf4b92ec4dd4decbb9c5fe6

config/allocator.gni

@@ -1,8 +1,9 @@
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
-
-if (is_android || cpu_arch == "mipsel" || is_mac || is_asan) {
+ 
+# TODO(GYP): Make tcmalloc work on win.
+if (is_android || cpu_arch == "mipsel" || is_mac || is_asan || is_win) {
   _default_allocator = "none"
 } else {
   _default_allocator = "tcmalloc"

config/compiler/BUILD.gn

@@ -918,15 +918,28 @@ config("optimize_max") {
   cflags = common_optimize_on_cflags
   ldflags = common_optimize_on_ldflags
   if (is_win) {
+    cflags -= [
+      "/Os",
+    ]
     cflags += [
       "/Ot",   # Favor speed over size.
-      "/GL",   # Whole program optimization.
-      # Disable Warning 4702 ("Unreachable code") for the WPO/PGO builds.
-      # Probably anything that this would catch that wouldn't be caught in a
-      # normal build isn't going to actually be a bug, so the incremental value
-      # of C4702 for PGO builds is likely very small.
-      "/wd4702",
     ]
+    if (is_official_build) {
+      # TODO(GYP): TODO(dpranke): Should these only be on in an official
+      # build, or on all the time? For now we'll require official build so
+      # that the compile is clean.
+      cflags += [
+        "/GL",   # Whole program optimization.
+        # Disable Warning 4702 ("Unreachable code") for the WPO/PGO builds.
+        # Probably anything that this would catch that wouldn't be caught in a
+        # normal build isn't going to actually be a bug, so the incremental
+        # value of C4702 for PGO builds is likely very small.
+        "/wd4702",
+      ]
+      ldflags += [
+        "/LTCG",
+      ]
+    }
   } else {
     cflags += [
       "-O2",

secondary/third_party/nss/BUILD.gn

@@ -1159,6 +1159,10 @@ if (is_linux) {
           "USE_HW_AES",
           "INTEL_GCM",
         ]
+        sources -= [
+          "nss/lib/freebl/mpi/mpi_amd64.c",
+        ]
+
       } else if (cpu_arch == "x64") {
         sources -= [
           "nss/lib/freebl/intel-aes-x86-masm.asm",