Remove libs/clock in favor of luci-go/common/clock.

go/src/infra/libs/clock/context.go

-// Copyright 2015 The Chromium 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 clock
-
-import (
-        "time"
-
-        "golang.org/x/net/context"
-)
-
-// Context key for clock.
-type clockKeyType int
-
-// Unique value for clock key.
-var clockKey clockKeyType
-
-// Factory is a generator function that produces a Clock instnace.
-type Factory func(context.Context) Clock
-
-// SetFactory creates a new Context using the supplied Clock factory.
-func SetFactory(ctx context.Context, f Factory) context.Context {
-        return context.WithValue(ctx, clockKey, f)
-}
-
-// Set creates a new Context using the supplied Clock.
-func Set(ctx context.Context, c Clock) context.Context {
-        return SetFactory(ctx, func(context.Context) Clock { return c })
-}
-
-// Get returns the Clock set in the supplied Context, defaulting to
-// SystemClock() if none is set.
-func Get(ctx context.Context) (clock Clock) {
-        v := ctx.Value(clockKey)
-        if v != nil {
-                f := v.(Factory)
-                if f != nil {
-                        clock = f(ctx)
-                }
-        }
-        if clock == nil {
-                clock = GetSystemClock()
-        }
-        return
-}
-
-//
-// "Implement" the Clock interface at the package level.
-//
-
-// Now calls Clock.Now on the Clock instance stored in the supplied Context.
-func Now(ctx context.Context) time.Time {
-        return Get(ctx).Now()
-}
-
-// Sleep calls Clock.Sleep on the Clock instance stored in the supplied Context.
-func Sleep(ctx context.Context, d time.Duration) {
-        Get(ctx).Sleep(d)
-}
-
-// NewTimer calls Clock.NewTimer on the Clock instance stored in the supplied
-// Context.
-func NewTimer(ctx context.Context) Timer {
-        return Get(ctx).NewTimer()
-}
-
-// After calls Clock.After on the Clock instance stored in the supplied Context.
-func After(ctx context.Context, d time.Duration) <-chan time.Time {
-        return Get(ctx).After(d)
-}