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/seq/seq.go

-// 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 seq implements the machine-dependent seq serialization format.
-//
-// Implementations of Transact and FinalizeRef are provided by a
-// specific foreign language binding package, e.g. go.mobile/bind/java.
-//
-// Designed only for use by the code generated by gobind. Don't try to
-// use this directly.
-package seq // import "golang.org/x/mobile/bind/seq"
-
-// TODO(crawshaw):
-//      There is opportunity for optimizing these language
-//      bindings which requires deconstructing seq into something
-//      gnarly. So don't get too attached to the design.
-
-import "fmt"
-
-// Transact calls a method on a foreign object instance.
-// It blocks until the call is complete.
-var Transact func(ref *Ref, code int, in *Buffer) (out *Buffer)
-
-// FinalizeRef is the finalizer used on foreign objects.
-var FinalizeRef func(ref *Ref)
-
-// A Func can be registered and called by a foreign language.
-type Func func(out, in *Buffer)
-
-// Registry holds functions callable from gobind generated bindings.
-// Functions are keyed by descriptor and function code.
-var Registry = make(map[string]map[int]Func)
-
-// Register registers a function in the Registry.
-func Register(descriptor string, code int, fn Func) {
-        m := Registry[descriptor]
-        if m == nil {
-                m = make(map[int]Func)
-                Registry[descriptor] = m
-        }
-        if m[code] != nil {
-                panic(fmt.Sprintf("registry.Register: %q/%d already registered", descriptor, code))
-        }
-        m[code] = fn
-}