Make goma work on win GN builds.

build/config/BUILDCONFIG.gn

Index: build/config/BUILDCONFIG.gn
diff --git a/build/config/BUILDCONFIG.gn b/build/config/BUILDCONFIG.gn
index 0d65c44da6405e085e737fc6ad50a1f47a13fdbb..6718767e9d5a37e319ddeb8a7e3e28c143b388a0 100644
--- a/build/config/BUILDCONFIG.gn
+++ b/build/config/BUILDCONFIG.gn
@@ -373,8 +373,14 @@ if (symbol_level == -1) {
 }
 
 # Symbol setup.
+import("//build/toolchain/goma.gni")

[brettw, 2014/11/21 05:28:03]

This will make all goma variables global. I'd like to discuss other ways to do
this. Will be busty Friday, maybe we can discuss Monday.

[Dirk Pranke, 2014/11/21 17:00:57]

ok.

 if (symbol_level == 2) {
-  _default_symbols_config = "//build/config/compiler:symbols"
+  if (is_win && use_goma) {
+    # GOMA doesn't support full symbols on Win.

[scottmg, 2014/11/21 02:35:41]

Make this TODO(): we don't handle /Z7 yet, so avoid PDB for now.

[Dirk Pranke, 2014/11/21 02:46:00]

Will do.

+    _default_symbols_config = "//build/config/compiler:minimal_symbols"
+  } else {
+    _default_symbols_config = "//build/config/compiler:symbols"
+  }
 } else if (symbol_level == 1) {
   _default_symbols_config = "//build/config/compiler:minimal_symbols"
 } else if (symbol_level == 0) {