Remove internal/sync

nosync package for GopherJS is problematic since nosync's mutex
assumes that Lock call is never duplicated, which is not true in
actual applications.

See also #603.

inpututil/inpututil.go

@@ -19,10 +19,10 @@ package inpututil
 
 import (
 	"sort"
+	"sync"
 
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/internal/hooks"
-	"github.com/hajimehoshi/ebiten/internal/sync"
 )
 
 type inputState struct {

internal/clock/clock.go

@@ -25,9 +25,8 @@
 package clock
 
 import (
+	"sync"
 	"time"
-
-	"github.com/hajimehoshi/ebiten/internal/sync"
 )
 
 const FPS = 60

internal/shareable/shareable.go

@@ -19,13 +19,13 @@ import (
 	"image"
 	"image/color"
 	"runtime"
+	"sync"
 
 	"github.com/hajimehoshi/ebiten/internal/affine"
 	"github.com/hajimehoshi/ebiten/internal/graphics"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 	"github.com/hajimehoshi/ebiten/internal/packing"
 	"github.com/hajimehoshi/ebiten/internal/restorable"
-	"github.com/hajimehoshi/ebiten/internal/sync"
 )
 
 type backend struct {

internal/sync/sync_js.go

@@ -1,29 +0,0 @@
-// Copyright 2017 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build js
-
-package sync
-
-import (
-	"github.com/gopherjs/gopherjs/nosync"
-)
-
-type Mutex struct {
-	nosync.Mutex
-}
-
-type RWMutex struct {
-	nosync.RWMutex
-}

internal/sync/sync_notjs.go

@@ -1,29 +0,0 @@
-// Copyright 2017 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build !js
-
-package sync
-
-import (
-	"sync"
-)
-
-type Mutex struct {
-	sync.Mutex
-}
-
-type RWMutex struct {
-	sync.RWMutex
-}

text/text.go

@@ -21,12 +21,12 @@ import (
 	"image"
 	"image/color"
 	"math"
+	"sync"
 
 	"golang.org/x/image/font"
 	"golang.org/x/image/math/fixed"
 
 	"github.com/hajimehoshi/ebiten"
-	"github.com/hajimehoshi/ebiten/internal/sync"
 )
 
 var (