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

chrome/common/BUILD.gn

Index: chrome/common/BUILD.gn
diff --git a/chrome/common/BUILD.gn b/chrome/common/BUILD.gn
index e740125e5e4d890ed947113ecc69fd05453b5660..02ea962f0785a888110389078e044a3af8e063fe 100644
--- a/chrome/common/BUILD.gn
+++ b/chrome/common/BUILD.gn
@@ -137,9 +137,7 @@ static_library("common") {
   }
 
   if (enable_nacl) {
-    deps += [
-      #'<(DEPTH)/components/nacl.gyp:nacl_common',  TODO(GYP)
-    ]
+    deps += [ "//components/nacl:nacl_common" ]
   }
 
   # Printing.
@@ -284,9 +282,7 @@ static_library("constants") {
   ]
 
   if (enable_nacl) {
-    deps += [
-      #'../components/nacl.gyp:nacl_switches',  TODO(GYP)
-    ]
+    deps += [ "//components/nacl:nacl_switches" ]
   }
 }