Add some remoting targets to GN build.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index b5c99e83ff93df73b12d3ebf8a79ba8ed0149f0a..4e7f562a28c752f99d38ea8c6ccb1960a2ca596d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -65,6 +65,7 @@ group("root") {
     "//pdf",
     "//ppapi:ppapi_c",
     "//printing",
+    "//remoting/client/plugin",
     "//sandbox",
     "//sdch",
     "//skia",
@@ -224,6 +225,7 @@ group("root") {
 
       # Not tested on Android yet:
       "//google_apis/gcm",
+      "//remoting/client/plugin",
       "//third_party/cld_2",
       "//third_party/libaddressinput",
       "//third_party/ffmpeg",