mobile: limit app/font/gl packages to linux/darwin.

They don't make sense for other platforms yet.

See golang/go#9603

Change-Id: I2ed269a00b1e1961aadf0a47fc95bbe3cd230113
Reviewed-on: https://go-review.googlesource.com/2902
Reviewed-by: David Crawshaw <[email protected]>

Author: hyangah

app/app.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux darwin
+
 package app
 
 import (

font/font.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux darwin
+
 // Package font provides platform independent access to system fonts.
 package font
 

gl/gendebug.go

@@ -11,8 +11,8 @@ package main
 
 import (
 	"bytes"
-	"fmt"
 	"flag"
+	"fmt"
 	"go/ast"
 	"go/format"
 	"go/parser"
@@ -221,6 +221,7 @@ const preamble = `// Copyright 2014 The Go Authors.  All rights reserved.
 // Generated from gl.go using go generate. DO NOT EDIT.
 // See doc.go for details.
 
+// +build linux darwin
 // +build gldebug
 
 package gl

gl/gl.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux darwin
 // +build !gldebug
 
 package gl

gl/gldebug.go

@@ -5,6 +5,7 @@
 // Generated from gl.go using go generate. DO NOT EDIT.
 // See doc.go for details.
 
+// +build linux darwin
 // +build gldebug
 
 package gl

gl/types_common.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux darwin
+
 package gl
 
 // This file contains GL Types and their methods that are independent of the

gl/types_debug.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux darwin
 // +build gldebug
 
 package gl

gl/types_prod.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux darwin
 // +build !gldebug
 
 package gl