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/sprite/sprite.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 sprite provides a 2D scene graph for rendering and animation.
-//
-// A tree of nodes is drawn by a rendering Engine, provided by another
-// package. The OS-independent Go version based on the image package is:
-//
-//      golang.org/x/mobile/sprite/portable
-//
-// An Engine draws a screen starting at a root Node. The tree is walked
-// depth-first, with affine transformations applied at each level.
-//
-// Nodes are rendered relative to their parent.
-//
-// Typical main loop:
-//
-//      for each frame {
-//              quantize time.Now() to a clock.Time
-//              process UI events
-//              modify the scene's nodes and animations (Arranger values)
-//              e.Render(scene, t)
-//      }
-package sprite // import "golang.org/x/mobile/sprite"
-
-import (
-        "image"
-        "image/draw"
-
-        "golang.org/x/mobile/f32"
-        "golang.org/x/mobile/sprite/clock"
-)
-
-type Arranger interface {
-        Arrange(e Engine, n *Node, t clock.Time)
-}
-
-type Texture interface {
-        Bounds() (w, h int)
-        Download(r image.Rectangle, dst draw.Image)
-        Upload(r image.Rectangle, src image.Image)
-        Unload()
-}
-
-type SubTex struct {
-        T Texture
-        R image.Rectangle
-}
-
-type Engine interface {
-        Register(n *Node)
-        Unregister(n *Node)
-
-        LoadTexture(a image.Image) (Texture, error)
-
-        SetSubTex(n *Node, x SubTex)
-        SetTransform(n *Node, m f32.Affine) // sets transform relative to parent.
-
-        Render(scene *Node, t clock.Time)
-}
-
-// A Node is a renderable element and forms a tree of Nodes.
-type Node struct {
-        Parent, FirstChild, LastChild, PrevSibling, NextSibling *Node
-
-        Arranger Arranger
-
-        // EngineFields contains fields that should only be accessed by Engine
-        // implementations. It is exported because such implementations can be
-        // in other packages.
-        EngineFields struct {
-                // TODO: separate TexDirty and TransformDirty bits?
-                Dirty  bool
-                Index  int32
-                SubTex SubTex
-        }
-}
-
-// AppendChild adds a node c as a child of n.
-//
-// It will panic if c already has a parent or siblings.
-func (n *Node) AppendChild(c *Node) {
-        if c.Parent != nil || c.PrevSibling != nil || c.NextSibling != nil {
-                panic("sprite: AppendChild called for an attached child Node")
-        }
-        last := n.LastChild
-        if last != nil {
-                last.NextSibling = c
-        } else {
-                n.FirstChild = c
-        }
-        n.LastChild = c
-        c.Parent = n
-        c.PrevSibling = last
-}
-
-// RemoveChild removes a node c that is a child of n. Afterwards, c will have
-// no parent and no siblings.
-//
-// It will panic if c's parent is not n.
-func (n *Node) RemoveChild(c *Node) {
-        if c.Parent != n {
-                panic("sprite: RemoveChild called for a non-child Node")
-        }
-        if n.FirstChild == c {
-                n.FirstChild = c.NextSibling
-        }
-        if c.NextSibling != nil {
-                c.NextSibling.PrevSibling = c.PrevSibling
-        }
-        if n.LastChild == c {
-                n.LastChild = c.PrevSibling
-        }
-        if c.PrevSibling != nil {
-                c.PrevSibling.NextSibling = c.NextSibling
-        }
-        c.Parent = nil
-        c.PrevSibling = nil
-        c.NextSibling = nil
-}