Add GN build file for surface.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index e5e8dd3ed7b13402daef242cbff0e025f38c9229..befee95ea4cf2ed8ac3feaaa25e05c489bccd283 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -61,6 +61,7 @@ group("root") {
     "//ui/events",
     "//ui/gfx",
     "//ui/resources",
+    "//ui/surface",
     "//url",
   ]
 
@@ -83,6 +84,7 @@ group("root") {
       "//ui/base:ui_base",
       "//ui/events",
       "//ui/gfx",
+      "//ui/surface",

[brettw, 2014/05/16 16:57:04]

Is this because it depends on Skia? Can you put a comment here about why it's
excluded on Android so I know when I can remove it from this list? (I have a
patch to fix Skia on Android).

[tfarina, 2014/05/16 21:24:24]

Yes. It is because Android GN is targeting ARM and Skia does not build at this
config, it still pending some ARM stuff.
Done.

     ]
   }
 }