Revert "Add disable_goma for args.gn on win"

This reverts commit 953fcf3f.

Reason for revert: We want to set envvar directly.

Original change's description:
> Add disable_goma for args.gn on win
>
> Switching use_goma causes full rebuild due to command line update in build.ninja.
> I added disable_goma to set GOMA_DISABLED on environment.{x86,x64}.
>
> If we specify disable_goma=true, GOMA_DISABLED env is passed to gomacc.
> Then gomacc executes given argument instead of sending args to goma daemon.
>
> This will help toolchain maintainer to check difference of build behavior w/wo goma without rebuilding everything.
>
> Bug:
> Change-Id: Ie58958b5484d57be1c40fbbca363f1eef4b55c7e
> Reviewed-on: https://chromium-review.googlesource.com/768549
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
> Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#518134}

TBR=dpranke@chromium.org,brucedawson@chromium.org,tikuta@chromium.org

Change-Id: Ia2d510f4149b30cff3f8dc6c0b89e37190c39368
Reviewed-on: https://chromium-review.googlesource.com/1015860Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551602}

build/config/win/BUILD.gn

@@ -13,12 +13,6 @@ import("//build/toolchain/toolchain.gni")
 
 assert(is_win)
 
-if (disable_goma) {
-  goma_disabled = "true"
-} else {
-  goma_disabled = "false"
-}
-
 declare_args() {
   # Set this to true to enable static analysis through Visual Studio's
   # /analyze. This dramatically slows compiles and reports thousands of
@@ -319,7 +313,6 @@ config("sdk_link") {
                                         current_os,
                                         current_cpu,
                                         "none",
-                                        goma_disabled,
                                       ],
                                       "scope")
 

build/toolchain/goma.gni

@@ -8,10 +8,6 @@ declare_args() {
   # Set to true to enable distributed compilation using Goma.
   use_goma = false
 
-  # Set to true to disable goma without update of command line.
-  # Changing this value does not cause full rebuild.
-  disable_goma = false
-
   # Set the default value based on the platform.
   if (host_os == "win") {
     # Absolute directory containing the gomacc.exe binary.
@@ -29,6 +25,3 @@ declare_args() {
 
 assert(!(is_win && host_os != "win") || !use_goma,
        "goma does not yet work in win cross builds, b/64390790")
-
-assert(!disable_goma || use_goma,
-       "disable_goma = true has no meaning if use_goma = false")

build/toolchain/win/BUILD.gn

@@ -32,12 +32,6 @@ if (use_goma) {
   goma_prefix = ""
 }
 
-if (disable_goma) {
-  goma_disabled = "true"
-} else {
-  goma_disabled = "false"
-}
-
 # Copy the VS runtime DLL for the default toolchain to the root build directory
 # so things will run.
 if (current_toolchain == default_toolchain) {
@@ -130,13 +124,7 @@ template("msvc_toolchain") {
     # %PATH%) -- e.g. 32-bit MSVS builds require %PATH% to be set and just
     # passing in a list of include directories isn't enough.
     if (defined(invoker.sys_include_flags)) {
-      if (disable_goma) {
-        # If disable_goma = true, need to pass GOMA_DISABLED env to
-        # gomacc.exe via environment.{x86,x64}.
-        env_wrapper = "ninja -t msvc -e $env -- "  # Note trailing space.
-      } else {
-        env_wrapper = ""
-      }
+      env_wrapper = ""
       sys_include_flags = "${invoker.sys_include_flags} "  # Note trailing space.
     } else {
       # clang-cl doesn't need this env hoop, so omit it there.
@@ -360,7 +348,6 @@ if (target_os == "win" &&
                                             target_os,
                                             target_cpu,
                                             "environment." + target_cpu,
-                                            goma_disabled,
                                           ],
                                           "scope")
 
@@ -397,7 +384,6 @@ x64_toolchain_data = exec_script("setup_toolchain.py",
                                    "win",
                                    "x64",
                                    "environment.x64",
-                                   goma_disabled,
                                  ],
                                  "scope")
 
@@ -463,7 +449,6 @@ if (target_os == "winuwp") {
                                            target_os,
                                            target_cpu,
                                            "environment.store_" + target_cpu,
-                                           goma_disabled,
                                          ],
                                          "scope")
 

build/toolchain/win/setup_toolchain.py

@@ -182,11 +182,11 @@ def _LowercaseDict(d):
 
 
 def main():
-  if len(sys.argv) != 8:
+  if len(sys.argv) != 7:
     print('Usage setup_toolchain.py '
           '<visual studio path> <win sdk path> '
           '<runtime dirs> <target_os> <target_cpu> '
-          '<environment block name|none> <goma_disabled>')
+          '<environment block name|none>')
     sys.exit(2)
   win_sdk_path = sys.argv[2]
   runtime_dirs = sys.argv[3]
@@ -195,7 +195,6 @@ def main():
   environment_block_name = sys.argv[6]
   if (environment_block_name == 'none'):
     environment_block_name = ''
-  goma_disabled = sys.argv[7]
 
   if (target_os == 'winuwp'):
     target_store = True
@@ -218,7 +217,6 @@ def main():
       # Extract environment variables for subprocesses.
       env = _LoadToolchainEnv(cpu, win_sdk_path, target_store)
       env['PATH'] = runtime_dirs + os.pathsep + env['PATH']
-      env['GOMA_DISABLED'] = goma_disabled
 
       for path in env['PATH'].split(os.pathsep):
         if os.path.exists(os.path.join(path, 'cl.exe')):