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

build/toolchain/win/BUILD.gn

Index: build/toolchain/win/BUILD.gn
diff --git a/build/toolchain/win/BUILD.gn b/build/toolchain/win/BUILD.gn
index 4fb72797d5f279cccb8b68c257a25fccd33725e0..858e9b4f4902bdea1a3e3fab4476f53a2489420e 100644
--- a/build/toolchain/win/BUILD.gn
+++ b/build/toolchain/win/BUILD.gn
@@ -225,9 +225,12 @@ template("msvc_toolchain") {
       if (defined(invoker.toolchain_os)) {
         current_os = invoker.toolchain_os
       }
-      if (defined(invoker.is_clang)) {
-        is_clang = invoker.is_clang
-      }
+
+      forward_variables_from(invoker,
+                             [
+                               "is_clang",
+                               "is_component_build",
+                             ])
 
       # This value needs to be passed through unchanged.
       host_toolchain = host_toolchain
@@ -284,21 +287,58 @@ x64_toolchain_data = exec_script("setup_toolchain.py",
                                  ],
                                  "scope")
 
-msvc_toolchain("x64") {
-  environment = "environment.x64"
-  toolchain_cpu = "x64"
-  cl = "${goma_prefix}\"${x64_toolchain_data.vc_bin_dir}/cl.exe\""
-  is_clang = false
+template("win_x64_toolchains") {
+  # TODO(mcgrathr): These assignments are only required because of
+  # crbug.com/395883.  Drop them if that ever gets fixed in GN.
+  concurrent_links = invoker.concurrent_links
+  goma_prefix = invoker.goma_prefix
+  x64_toolchain_data = invoker.x64_toolchain_data
+  clang_cl = invoker.clang_cl
+
+  msvc_toolchain(target_name) {
+    environment = "environment.x64"
+    toolchain_cpu = "x64"
+    cl = "${goma_prefix}\"${x64_toolchain_data.vc_bin_dir}/cl.exe\""
+    is_clang = false
+
+    forward_variables_from(invoker, [ "is_component_build" ])
+  }
+
+  msvc_toolchain("clang_" + target_name) {
+    environment = "environment.x64"
+    toolchain_cpu = "x64"
+    prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
+                         root_build_dir)
+    cl = "${goma_prefix}$prefix/${clang_cl}"
+    toolchain_os = "win"
+    is_clang = true
+
+    forward_variables_from(invoker, [ "is_component_build" ])
+  }
+}
+
+win_x64_toolchains("x64") {
+  # TODO(mcgrathr): These assignments are only required because of
+  # crbug.com/395883.  Drop them if that ever gets fixed in GN.
+  concurrent_links = concurrent_links
+  goma_prefix = goma_prefix
+  x64_toolchain_data = x64_toolchain_data
 }
 
-msvc_toolchain("clang_x64") {
-  environment = "environment.x64"
-  toolchain_cpu = "x64"
-  prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
-                       root_build_dir)
-  cl = "${goma_prefix}$prefix/${clang_cl}"
-  toolchain_os = "win"
-  is_clang = true
+# The nacl_win64 toolchain is nearly identical to the plain x64 toolchain.
+# It's used solely for building nacl64.exe (//components/nacl/broker:nacl64).
+# The only reason it's a separate toolchain is so that it can force
+# is_component_build to false in the toolchain_args() block, because
+# building nacl64.exe in component style does not work.
+win_x64_toolchains("nacl_win64") {
+  is_component_build = false
+
+  # TODO(mcgrathr): These assignments are only required because of
+  # crbug.com/395883.  Drop them if that ever gets fixed in GN.
+  concurrent_links = concurrent_links
+  goma_prefix = goma_prefix
+  x64_toolchain_data = x64_toolchain_data
+  clang_cl = clang_cl
 }
 
 # WinRT toolchains. Only define these when targeting them.