Update from https://crrev.com/327068

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 e9461a4644b4f5a88174cecb1216209cf04b7dcd..05406c39d42cec7a49e7b60263bb55a1a1a8d851 100644
--- a/build/toolchain/win/BUILD.gn
+++ b/build/toolchain/win/BUILD.gn
@@ -101,7 +101,7 @@ template("msvc_toolchain") {
       outputs = [
         "{{source_out_dir}}/{{target_output_name}}.{{source_name_part}}.obj",
       ]
-      rspfile_content = "{{defines}} {{include_dirs}} {{cflags}} {{cflags_c}}"
+      rspfile_content = "{{defines}} {{include_dirs}} {{cflags}} {{cflags_cc}}"
     }
 
     tool("rc") {
@@ -201,9 +201,6 @@ template("msvc_toolchain") {
     # passed to the build. They are ignored when this is the default toolchain.
     toolchain_args() {
       current_cpu = invoker.current_cpu
-
-      # TODO(dpranke): cpu_arch is here for backwards compatibility.
-      cpu_arch = current_cpu
     }
   }
 }