Add some remoting targets to GN build.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 9485121694ec24e35f2f42453a2de2d3e8cf12ba..1b81c35c878567bd5d3bf55651ea1782022caf5f 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -66,6 +66,7 @@ group("root") {
     "//pdf",
     "//ppapi:ppapi_c",
     "//printing",
+    "//remoting/client/plugin",
     "//sandbox",
     "//sdch",
     "//skia",
@@ -227,6 +228,7 @@ group("root") {
 
       # Not tested on Android yet:
       "//google_apis/gcm",
+      "//remoting/client/plugin",
       "//third_party/cld_2",
       "//third_party/libaddressinput",
       "//third_party/ffmpeg",