Land prep work to enable NaCl in the Linux x64 GN builds.

ppapi/shared_impl/BUILD.gn

Index: ppapi/shared_impl/BUILD.gn
diff --git a/ppapi/shared_impl/BUILD.gn b/ppapi/shared_impl/BUILD.gn
index 14c65bc2b34d72a900a94007a741748b20a56d45..59f4ec05ee333afbdc8a0d0c6e28fda7b0c5d791 100644
--- a/ppapi/shared_impl/BUILD.gn
+++ b/ppapi/shared_impl/BUILD.gn
@@ -172,13 +172,18 @@ component("shared_impl") {
     "//media:shared_memory_support",
     "//ppapi/c",
     "//ppapi/thunk",
-    "//skia",
     "//third_party/icu:icuuc",
-    "//ui/events:events_base",
-    "//ui/surface",
     "//url",
   ]
 
+  if (!is_nacl) {
+    deps += [
+      "//skia",
+      "//ui/events:events_base",
+      "//ui/surface",
+    ]
+  }
+
   if (is_mac) {
     libs = [ "QuartzCore.framework" ]
   }