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

ipc/BUILD.gn

Index: ipc/BUILD.gn
diff --git a/ipc/BUILD.gn b/ipc/BUILD.gn
index f54ff07f9f033c519df492c93047c13895568b08..e37e48a386f24c62b2891fc74d463ede594d64c4 100644
--- a/ipc/BUILD.gn
+++ b/ipc/BUILD.gn
@@ -67,7 +67,13 @@ component("ipc") {
     "unix_domain_socket_util.h",
   ]
 
-  if (!is_nacl) {
+  if (is_nacl) {
+    sources -= [
+      "ipc_channel.cc",
+      "ipc_channel_posix.cc",
+      "unix_domain_socket_util.cc",
+    ]
+  } else {
     sources -= [
       "ipc_channel_nacl.cc",
       "ipc_channel_nacl.h",
@@ -82,10 +88,14 @@ component("ipc") {
 
   deps = [
     "//base",
-
-    # TODO(viettrungluu): Needed for base/lazy_instance.h, which is suspect.
-    "//base/third_party/dynamic_annotations",
   ]
+
+  if (!is_nacl) {
+    deps += [
+      # TODO(viettrungluu): Needed for base/lazy_instance.h, which is suspect.
+      "//base/third_party/dynamic_annotations",
+    ]
+  }
 }
 
 # TODO(dpranke): crbug.com/360936. Get this to build and run on Android.
@@ -149,7 +159,6 @@ if (!is_android) {
     #    deps += "//base/allocator"
     #  }
     #}
-
     deps = [
       ":ipc",
       ":test_support",