Add checkout_nacl gclient flag (default true) (attempt chromium#3).

This is a straight (merged) re-land of {#507355}, since
the bug in gclient that this tickled was fixed.

See https://groups.google.com/a/chromium.org/d/msg/chromium-dev/tO8kIrDtQc8/bCRO-UXxBQAJ
for discussion.

TBR=phajdan.jr@chromium.org, bradnelson@chromium.org
BUG=756688

Change-Id: Ife1ed0f30285828e37170306e2723fd70f591d6d
Reviewed-on: https://chromium-review.googlesource.com/750363
Commit-Queue: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513416}

BUILD.gn

@@ -686,10 +686,10 @@ group("gn_all") {
       if (!is_android) {
         deps += [ "//chrome/test:load_library_perf_tests" ]
       }
-      deps += [
-        "//native_client/src/trusted/platform_qualify:vcpuid",
-        "//third_party/libjpeg_turbo:simd_asm",
-      ]
+      if (enable_nacl) {
+        deps += [ "//native_client/src/trusted/platform_qualify:vcpuid" ]
+      }
+      deps += [ "//third_party/libjpeg_turbo:simd_asm" ]
     }
     if (is_linux && current_toolchain == host_toolchain) {
       deps += [ "//v8:v8_shell" ]

DEPS

@@ -26,6 +26,11 @@
 #  git commit -a
 #  git cl upload
 
+gclient_gn_args_file = 'src/build/config/gclient_args.gni'
+gclient_gn_args = [
+  'checkout_nacl',
+]
+
 
 vars = {
   # By default, we should check out everything needed to run on the main
@@ -34,6 +39,10 @@ vars = {
   # purposes.
   'checkout_configuration': 'default',
 
+  # Check out and download nacl by default. This can be disabled e.g. with
+  # custom_vars.
+  'checkout_nacl': True,
+
   # By default, do not check out src-internal. This can be overridden e.g. with
   # custom_vars.
   'checkout_src_internal': False,
@@ -215,8 +224,10 @@ deps = {
   'src/media/cdm/api':
     Var('chromium_git') + '/chromium/cdm.git' + '@' + 'ea5df8e78fbd0a4c24cc3a1f3faefefcd1b45237',
 
-  'src/native_client':
-    Var('chromium_git') + '/native_client/src/native_client.git' + '@' + Var('nacl_revision'),
+  'src/native_client': {
+      'url': Var('chromium_git') + '/native_client/src/native_client.git' + '@' + Var('nacl_revision'),
+      'condition': 'checkout_nacl',
+  },
 
   'src/third_party/SPIRV-Tools/src':
     Var('chromium_git') + '/external/github.com/KhronosGroup/SPIRV-Tools.git' + '@' + '9166854ac93ef81b026e943ccd230fed6c8b8d3c',
@@ -353,7 +364,7 @@ deps = {
   # GNU binutils assembler for x86-32.
   'src/third_party/gnu_binutils': {
       'url': Var('chromium_git') + '/native_client/deps/third_party/gnu_binutils.git' + '@' + 'f4003433b61b25666565690caf3d7a7a1a4ec436',
-      'condition': 'checkout_win',
+      'condition': 'checkout_nacl and checkout_win',
   },
 
   'src/third_party/gperf': {
@@ -470,7 +481,7 @@ deps = {
   # GNU binutils assembler for x86-64.
   'src/third_party/mingw-w64/mingw/bin': {
       'url': Var('chromium_git') + '/native_client/deps/third_party/mingw-w64/mingw/bin.git' + '@' + '3cc8b140b883a9fe4986d12cfd46c16a093d3527',
-      'condition': 'checkout_win',
+      'condition': 'checkout_nacl and checkout_win',
   },
 
   # Graphics buffer allocator for Chrome OS.
@@ -493,7 +504,7 @@ deps = {
   # Binaries for nacl sdk.
   'src/third_party/nacl_sdk_binaries': {
       'url': Var('chromium_git') + '/chromium/deps/nacl_sdk_binaries.git' + '@' + '759dfca03bdc774da7ecbf974f6e2b84f43699a5',
-      'condition': 'checkout_win',
+      'condition': 'checkout_nacl and checkout_win',
   },
 
   'src/third_party/netty-tcnative/src': {
@@ -714,6 +725,7 @@ hooks = [
     # anywhere from 30 minutes to 4 hours depending on platform to build.
     'name': 'nacltools',
     'pattern': '.',
+    'condition': 'checkout_nacl',
     'action': [
         'python',
         'src/build/download_nacl_toolchains.py',

build/.gitignore

@@ -2,6 +2,7 @@
 # mirror in DEPS. Without it, a lot is wiped and re-downloaded for each sync.
 /android/bin
 /android/binary_size/apks/**/*.apk
+/config/gclient_args.gni
 /Debug
 /Debug_x64
 /goma

components/nacl/features.gni

@@ -3,14 +3,15 @@
 # found in the LICENSE file.
 
 import("//build/config/chromecast_build.gni")
+import("//build/config/gclient_args.gni")
 
 declare_args() {
   # Enables Native Client support.
   # Temporarily disable nacl on arm64 linux to get rid of compilation errors.
   # TODO: When mipsel-nacl-clang is available, drop the exclusion.
   enable_nacl =
-      !is_ios && !is_android && !is_fuchsia && !is_chromecast &&
-      current_cpu != "mipsel" && current_cpu != "mips64el" &&
+      checkout_nacl && !is_ios && !is_android && !is_fuchsia &&
+      !is_chromecast && current_cpu != "mipsel" && current_cpu != "mips64el" &&
       !(is_linux && target_cpu == "arm64") && !(is_win && host_os != "win")
 
   # Non-SFI is not yet supported on mipsel
@@ -19,3 +20,4 @@ declare_args() {
 
 assert(!(is_win && host_os != "win") || !enable_nacl,
        "NaCl doesn't work in win cross builds, crbug.com/774186")
+assert(!enable_nacl || checkout_nacl)