Expose MGL interface through NaCl IRT

mojo/public/c/gpu/BUILD.gn

Index: mojo/public/c/gpu/BUILD.gn
diff --git a/mojo/public/c/gpu/BUILD.gn b/mojo/public/c/gpu/BUILD.gn
index 51fa69a2ef8c88992f8bd990b9cf1788765f3224..48fd89e811d6684d6e18399c4843cf3d0b26ef88 100644
--- a/mojo/public/c/gpu/BUILD.gn
+++ b/mojo/public/c/gpu/BUILD.gn
@@ -16,9 +16,11 @@ group("gpu") {
     ":MGL",
     ":MGL_signal_sync_point",
     ":GLES2",
-    "../../platform/native:mgl_thunks",
     "../../platform/native:gles2",
   ]
+  if (!is_nacl) {
+    deps += [ "../../platform/native:mgl_thunks" ]
+  }
 }
 
 group("gpu_onscreen") {
@@ -28,8 +30,10 @@ group("gpu_onscreen") {
 
   deps = [
     ":gpu",
-    "../../platform/native:mgl_onscreen_thunks",
   ]
+  if (!is_nacl) {
+    deps += [ "../../platform/native:mgl_onscreen_thunks" ]
+  }
 }
 
 mojo_sdk_source_set("MGL") {