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/app/x11.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.
-
-// +build linux,!android
-
-package app
-
-/*
-Simple on-screen app debugging for X11. Not an officially supported
-development target for apps, as screens with mice are very different
-than screens with touch panels.
-
-On Ubuntu 14.04 'Trusty', you may have to install these libraries:
-sudo apt-get install libegl1-mesa-dev libgles2-mesa-dev libx11-dev
-*/
-
-/*
-#cgo LDFLAGS: -lEGL -lGLESv2 -lX11
-
-void runApp(void);
-*/
-import "C"
-import (
-        "runtime"
-        "sync"
-
-        "golang.org/x/mobile/event"
-        "golang.org/x/mobile/geom"
-)
-
-var cb Callbacks
-
-func run(callbacks Callbacks) {
-        runtime.LockOSThread()
-        cb = callbacks
-        C.runApp()
-}
-
-//export onResize
-func onResize(w, h int) {
-        // TODO(nigeltao): don't assume 72 DPI. DisplayWidth / DisplayWidthMM
-        // is probably the best place to start looking.
-        geom.PixelsPerPt = 1
-        geom.Width = geom.Pt(w)
-        geom.Height = geom.Pt(h)
-}
-
-var events struct {
-        sync.Mutex
-        pending []event.Touch
-}
-
-func sendTouch(ty event.TouchType, x, y float32) {
-        events.Lock()
-        events.pending = append(events.pending, event.Touch{
-                Type: ty,
-                Loc: geom.Point{
-                        X: geom.Pt(x),
-                        Y: geom.Pt(y),
-                },
-        })
-        events.Unlock()
-}
-
-//export onTouchStart
-func onTouchStart(x, y float32) { sendTouch(event.TouchStart, x, y) }
-
-//export onTouchMove
-func onTouchMove(x, y float32) { sendTouch(event.TouchMove, x, y) }
-
-//export onTouchEnd
-func onTouchEnd(x, y float32) { sendTouch(event.TouchEnd, x, y) }
-
-//export onDraw
-func onDraw() {
-        events.Lock()
-        pending := events.pending
-        events.pending = nil
-        events.Unlock()
-
-        for _, e := range pending {
-                if cb.Touch != nil {
-                        cb.Touch(e)
-                }
-        }
-        if cb.Draw != nil {
-                cb.Draw()
-        }
-}