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/audio/audio_test.go

Index: third_party/go/src/golang.org/x/mobile/audio/audio_test.go
diff --git a/third_party/go/src/golang.org/x/mobile/audio/audio_test.go b/third_party/go/src/golang.org/x/mobile/audio/audio_test.go
deleted file mode 100644
index a652b114aec5bae4aea6abe1ff8faf9e1ecc1bae..0000000000000000000000000000000000000000
--- a/third_party/go/src/golang.org/x/mobile/audio/audio_test.go
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright 2015 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.
-
-// +build darwin
-
-package audio
-
-import (
-	"testing"
-	"time"
-)
-
-func TestNoOp(t *testing.T) {
-	var p *Player
-	if err := p.Play(); err != nil {
-		t.Errorf("no-op player failed to play: %v", err)
-	}
-	if err := p.Pause(); err != nil {
-		t.Errorf("no-op player failed to pause: %v", err)
-	}
-	if err := p.Stop(); err != nil {
-		t.Errorf("no-op player failed to stop: %v", err)
-	}
-	if c := p.Current(); c != time.Duration(0) {
-		t.Errorf("no-op player returns a non-zero playback position: %v", c)
-	}
-	if tot := p.Total(); tot != time.Duration(0) {
-		t.Errorf("no-op player returns a non-zero total: %v", tot)
-	}
-	if vol := p.Volume(); vol != 0 {
-		t.Errorf("no-op player returns a non-zero total: %v", vol)
-	}
-	if s := p.State(); s != Unknown {
-		t.Errorf("playing state: %v", s)
-	}
-	p.SetVolume(0.1)
-	p.Seek(time.Duration(100))
-	p.Destroy()
-}