gn fixes for ui/gl and mac

third_party/mesa/BUILD.gn

Index: third_party/mesa/BUILD.gn
diff --git a/third_party/mesa/BUILD.gn b/third_party/mesa/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..f02aa4637b44de9c09d3984dfed7336503f133eb
--- /dev/null
+++ b/third_party/mesa/BUILD.gn
@@ -0,0 +1,16 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/ui.gni")
+
+config("mesa_headers_config") {

[jamesr, 2014/05/31 00:44:52]

can i get away with just a target? how do i fwd if i do this?

[brettw, 2014/05/31 04:11:28]

You need the config to forward. You can get away with only the config and no
target if you want to have people do

configs += [ "//third_party/mesa:mesa_headers_config" ]

instead of doing the deps thing.

+  include_dirs = [ "src/include" ]
+  if (use_x11) {
+    defines += [ "MESA_EGL_NO_X11_HEADERS" ]

[tfarina, 2014/05/31 23:24:17]

Linux GN bot is complaining about this:

ERROR at //third_party/mesa/BUILD.gn:10:5: Undefined variable for +=.
    defines += [ "MESA_EGL_NO_X11_HEADERS" ]
    ^------
I don't have something with this name in scope now.

I think the solution is to have it as:

defines = [ .... ] 

since you don't have a previous "defines" in this scope to have it as +=.

+  }
+}
+
+source_set("mesa_headers") {
+  direct_dependent_configs = [ ":mesa_headers_config" ]
+}