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/ref.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
-
-//#cgo LDFLAGS: -llog
-//#include <android/log.h>
-//#include <string.h>
-//import "C"
-
-import (
-        "fmt"
-        "sync"
-)
-
-// refs stores Go objects that have been passed to another language.
-var refs struct {
-        sync.Mutex
-        next int32 // next reference number to use for Go object, always negative
-        refs map[interface{}]int32
-        objs map[int32]interface{}
-}
-
-func init() {
-        refs.Lock()
-        refs.next = -24 // Go objects get negative reference numbers. Arbitrary starting point.
-        refs.refs = make(map[interface{}]int32)
-        refs.objs = make(map[int32]interface{})
-        refs.Unlock()
-}
-
-// A Ref represents a Java or Go object passed across the language
-// boundary.
-type Ref struct {
-        Num int32
-}
-
-// Get returns the underlying object.
-func (r *Ref) Get() interface{} {
-        refs.Lock()
-        obj, ok := refs.objs[r.Num]
-        refs.Unlock()
-        if !ok {
-                panic(fmt.Sprintf("unknown ref %d", r.Num))
-        }
-        return obj
-}
-
-// Delete remove the reference to the underlying object.
-func Delete(num int32) {
-        refs.Lock()
-        obj, ok := refs.objs[num]
-        if !ok {
-                panic(fmt.Sprintf("seq.Delete unknown refnum: %d", num))
-        }
-        delete(refs.objs, num)
-        delete(refs.refs, obj)
-        refs.Unlock()
-}