Add "filters/count" filter.

go/src/infra/gae/libs/gae/filters/count/gi.go

Index: go/src/infra/gae/libs/gae/filters/count/gi.go
diff --git a/go/src/infra/gae/libs/gae/filters/count/gi.go b/go/src/infra/gae/libs/gae/filters/count/gi.go
new file mode 100644
index 0000000000000000000000000000000000000000..21c48d2d56700e40afb98018b33c4639b15f769c
--- /dev/null
+++ b/go/src/infra/gae/libs/gae/filters/count/gi.go
@@ -0,0 +1,136 @@
+// 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 count
+
+import (
+	"golang.org/x/net/context"
+	"time"
+
+	"infra/gae/libs/gae"
+)
+
+// GICounter is the counter object for the GlobalInfo service.
+type GICounter struct {
+	AppID                  Entry
+	Datacenter             Entry
+	DefaultVersionHostname Entry
+	InstanceID             Entry
+	IsDevAppServer         Entry
+	IsOverQuota            Entry
+	IsTimeoutError         Entry
+	ModuleHostname         Entry
+	ModuleName             Entry
+	RequestID              Entry
+	ServerSoftware         Entry
+	ServiceAccount         Entry
+	VersionID              Entry
+	Namespace              Entry
+	AccessToken            Entry
+	PublicCertificates     Entry
+	SignBytes              Entry
+}
+
+type giCounter struct {
+	c *GICounter
+
+	gi gae.GlobalInfo
+}
+
+var _ gae.GlobalInfo = (*giCounter)(nil)
+
+func (g *giCounter) AppID() string {
+	g.c.AppID.up()
+	return g.gi.AppID()
+}
+
+func (g *giCounter) Datacenter() string {
+	g.c.Datacenter.up()
+	return g.gi.Datacenter()
+}
+
+func (g *giCounter) DefaultVersionHostname() string {
+	g.c.DefaultVersionHostname.up()
+	return g.gi.DefaultVersionHostname()
+}
+
+func (g *giCounter) InstanceID() string {
+	g.c.InstanceID.up()
+	return g.gi.InstanceID()
+}
+
+func (g *giCounter) IsDevAppServer() bool {
+	g.c.IsDevAppServer.up()
+	return g.gi.IsDevAppServer()
+}
+
+func (g *giCounter) IsOverQuota(err error) bool {
+	g.c.IsOverQuota.up()
+	return g.gi.IsOverQuota(err)
+}
+
+func (g *giCounter) IsTimeoutError(err error) bool {
+	g.c.IsTimeoutError.up()
+	return g.gi.IsTimeoutError(err)
+}
+
+func (g *giCounter) ModuleHostname(module, version, instance string) (string, error) {
+	ret, err := g.gi.ModuleHostname(module, version, instance)
+	return ret, g.c.ModuleHostname.up(err)
+}
+
+func (g *giCounter) ModuleName() string {
+	g.c.ModuleName.up()
+	return g.gi.ModuleName()
+}
+
+func (g *giCounter) RequestID() string {
+	g.c.RequestID.up()
+	return g.gi.RequestID()
+}
+
+func (g *giCounter) ServerSoftware() string {
+	g.c.ServerSoftware.up()
+	return g.gi.ServerSoftware()
+}
+
+func (g *giCounter) ServiceAccount() (string, error) {
+	ret, err := g.gi.ServiceAccount()
+	return ret, g.c.ServiceAccount.up(err)
+}
+
+func (g *giCounter) VersionID() string {
+	g.c.VersionID.up()
+	return g.gi.VersionID()
+}
+
+func (g *giCounter) Namespace(namespace string) (context.Context, error) {
+	ret, err := g.gi.Namespace(namespace)
+	return ret, g.c.Namespace.up(err)
+}
+
+func (g *giCounter) AccessToken(scopes ...string) (token string, expiry time.Time, err error) {
+	token, expiry, err = g.gi.AccessToken(scopes...)
+	g.c.AccessToken.up(err)
+	return
+}
+
+func (g *giCounter) PublicCertificates() ([]gae.GICertificate, error) {
+	ret, err := g.gi.PublicCertificates()
+	return ret, g.c.PublicCertificates.up(err)
+}
+
+func (g *giCounter) SignBytes(bytes []byte) (keyName string, signature []byte, err error) {
+	keyName, signature, err = g.gi.SignBytes(bytes)
+	g.c.SignBytes.up(err)
+	return
+}
+
+// FilterGI installs a counter GlobalInfo filter in the context.
+func FilterGI(c context.Context) (context.Context, *GICounter) {
+	state := &GICounter{}
+	return gae.AddGIFilters(c, func(ic context.Context, gi gae.GlobalInfo) gae.GlobalInfo {
+		return &giCounter{state, gi}
+	}), state
+}