First pass on blink compiling for GN build

Source/build/scripts/scripts.gni

Index: Source/build/scripts/scripts.gni
diff --git a/Source/build/scripts/scripts.gni b/Source/build/scripts/scripts.gni
index 6deafced50d9db33c02e379bf029e94a76987954..50f6ca8440062556584242b7f912a900ca63cddf 100644
--- a/Source/build/scripts/scripts.gni
+++ b/Source/build/scripts/scripts.gni
@@ -51,10 +51,22 @@ make_element_type_helpers_files = make_qualified_names_files + [
   "$_scripts_dir/templates/ElementTypeHelpers.h.tmpl",
 ]
 
-# gperf_exe is relative to the build directory. Don't rebase it because on
-# Posix we want to run the system one on the path.
+# The executables are relative to the build directory. Don't rebase it because
+# on Posix we want to run the system one on the path.
 if (is_win) {
+  perl_exe = rebase_path("//third_party/perl/perl/bin/perl.exe", root_build_dir)
   gperf_exe = rebase_path("//third_party/gperf/bin/gperf.exe", root_build_dir)
+  bison_exe = rebase_path("//third_party/bison/bin/bison.exe", root_build_dir)
+  # Using cl instead of cygwin gcc cuts the processing time from
+  # 1m58s to 0m52s.
+  preprocessor = "--preprocessor \"cl.exe -nologo -EP -TP\""
 } else {
+  perl_exe = "perl"
   gperf_exe = "gperf"
+  bison_exe = "bison"
+  # We specify a preprocess so it happens locally and won't get
+  # distributed to goma.
+  # FIXME: /usr/bin/gcc won't exist on OSX forever. We want to
+  # use /usr/bin/clang once we require Xcode 4.x.
+  preprocessor = "--preprocessor \"/usr/bin/gcc -E -P -x c++\""
 }