GN: Use special toolchain for nacl64.exe, force is_component_build off

components/nacl/broker/BUILD.gn

 # Copyright 2016 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.
 
 import("//build/config/features.gni")
 
 # This file builds nacl64.exe, which is a 64-bit x86 Windows executable
 # used only in the 32-bit x86 Windows build.  The :broker code runs both
 # in nacl64.exe and in the 32-bit chrome executable, to launch
 # nacl64.exe and communicate with it.
@@ skipping 40 matching lines @@
   # Tests, packaging rules, etc. will expect to find nacl64.exe in the root
   # of the output directory.  It gets built in a non-default toolchain and
   # so will be delivered in the toolchain output subdirectory.  So this
   # just copies it to the expected place.  Having this target also makes
   # it simpler for things to depend on nacl64, since they don't have to
   # use a toolchain qualifier.
   copy("nacl64") {
     # NOTE: This must match what //build/config/BUILDCONFIG.gn uses
     # as default toolchain for the corresponding x64 build.
     if (is_clang) {
-      x64_toolchain = "//build/toolchain/win:clang_x64"
+      x64_toolchain = "//build/toolchain/win:clang_nacl_win64"
     } else {
-      x64_toolchain = "//build/toolchain/win:x64"
+      x64_toolchain = "//build/toolchain/win:nacl_win64"
     }
     nacl64_label = ":nacl64($x64_toolchain)"
     nacl64_out_dir = get_label_info(nacl64_label, "root_out_dir")
     sources = [
       "$nacl64_out_dir/nacl64.exe",
     ]
     outputs = [
       "$root_out_dir/{{source_file_part}}",
     ]
     deps = [
       nacl64_label,
     ]
   }
 } else if (current_cpu == "x64") {
   # In the x64 toolchain context, build nacl64.exe for real.
   executable("nacl64") {
     configs += [ "//build/config/win:windowed" ]
 
     # //build/config/compiler:optimize{,_max} adds this for official builds
     # only, as it only reduces binary size and is not necessary for
     # correctness.  But for nacl64.exe, it makes more than a six-fold
-    # difference in the binary size, so always use it.
-    ldflags = [ "/OPT:REF" ]
+    # difference in the binary size, so always use it in release builds.
+    # Note that using this flag disables incremental linking.  In debug
+    # builds, incremental rebuild time is usually of more concern than
+    # binary size, so incremental linking is preferable to size reduction.
+    if (!is_debug) {
+      ldflags = [ "/OPT:REF" ]
+    }
 
     sources = [
       "//chrome/nacl/nacl_exe_win_64.cc",
     ]
 
     deps = [
       ":broker",
       ":nacl64_content",
       ":nacl64_crash_reporter_client",
       "//base",
@@ skipping 51 matching lines @@
       "//chrome/installer/util:with_no_strings",
       "//components/browser_watcher:browser_watcher_client",
       "//components/flags_ui:switches",
       "//components/policy",
       "//content/public/common:static_switches",
       "//ipc",
       "//third_party/kasko:kasko_features",
     ]
   }
 }