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/gl/glutil/glutil.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 glutil implements OpenGL utility functions.
-package glutil // import "golang.org/x/mobile/gl/glutil"
-
-import (
-        "fmt"
-
-        "golang.org/x/mobile/gl"
-)
-
-// CreateProgram creates, compiles, and links a gl.Program.
-func CreateProgram(vertexSrc, fragmentSrc string) (gl.Program, error) {
-        program := gl.CreateProgram()
-        if program.Value == 0 {
-                return gl.Program{}, fmt.Errorf("glutil: no programs available")
-        }
-
-        vertexShader, err := loadShader(gl.VERTEX_SHADER, vertexSrc)
-        if err != nil {
-                return gl.Program{}, err
-        }
-        fragmentShader, err := loadShader(gl.FRAGMENT_SHADER, fragmentSrc)
-        if err != nil {
-                gl.DeleteShader(vertexShader)
-                return gl.Program{}, err
-        }
-
-        gl.AttachShader(program, vertexShader)
-        gl.AttachShader(program, fragmentShader)
-        gl.LinkProgram(program)
-
-        // Flag shaders for deletion when program is unlinked.
-        gl.DeleteShader(vertexShader)
-        gl.DeleteShader(fragmentShader)
-
-        if gl.GetProgrami(program, gl.LINK_STATUS) == 0 {
-                defer gl.DeleteProgram(program)
-                return gl.Program{}, fmt.Errorf("glutil: %s", gl.GetProgramInfoLog(program))
-        }
-        return program, nil
-}
-
-func loadShader(shaderType gl.Enum, src string) (gl.Shader, error) {
-        shader := gl.CreateShader(shaderType)
-        if shader.Value == 0 {
-                return gl.Shader{}, fmt.Errorf("glutil: could not create shader (type %v)", shaderType)
-        }
-        gl.ShaderSource(shader, src)
-        gl.CompileShader(shader)
-        if gl.GetShaderi(shader, gl.COMPILE_STATUS) == 0 {
-                defer gl.DeleteShader(shader)
-                return gl.Shader{}, fmt.Errorf("shader compile: %s", gl.GetShaderInfoLog(shader))
-        }
-        return shader, nil
-}