Remove third_party/golang.org/x/mobile as it is no longer used with Go 1.5.

third_party/go/src/golang.org/x/mobile/bind/testdata/basictypes.go

Index: third_party/go/src/golang.org/x/mobile/bind/testdata/basictypes.go
diff --git a/third_party/go/src/golang.org/x/mobile/bind/testdata/basictypes.go b/third_party/go/src/golang.org/x/mobile/bind/testdata/basictypes.go
deleted file mode 100644
index bc0bffbcd1602232a43ec17aa23f2d1d8faba8c7..0000000000000000000000000000000000000000
--- a/third_party/go/src/golang.org/x/mobile/bind/testdata/basictypes.go
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 The Go Authors.  All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package basictypes
-
-func Ints(x int8, y int16, z int32, t int64, u int) {}
-
-func Error() error { return nil }
-
-func ErrorPair() (int, error) { return 0, nil }
-
-func ByteArrays(x []byte) []byte { return nil }