cmd/gobind: fix init_test.

$GOROOT instead of $HOME/go.

Change-Id: I6dd22057b58b0ad93ecbc6900a2fec09c41fe019
Reviewed-on: https://go-review.googlesource.com/6160
Reviewed-by: David Crawshaw <crawshaw@golang.org>
diff --git a/cmd/gomobile/build.go b/cmd/gomobile/build.go
index 7a324ec..3837eb4 100644
--- a/cmd/gomobile/build.go
+++ b/cmd/gomobile/build.go
@@ -252,6 +252,9 @@
 	if ndkccpath != "" {
 		cmd = strings.Replace(cmd, ndkccpath, "$NDKCCPATH", -1)
 	}
+	if goroot := goEnv("GOROOT"); goroot != "" {
+		cmd = strings.Replace(cmd, goroot, "$GOROOT", -1)
+	}
 	if env := os.Getenv("HOME"); env != "" {
 		cmd = strings.Replace(cmd, env, "$HOME", -1)
 	}
diff --git a/cmd/gomobile/init_test.go b/cmd/gomobile/init_test.go
index 26039d2..4dffbe0 100644
--- a/cmd/gomobile/init_test.go
+++ b/cmd/gomobile/init_test.go
@@ -66,10 +66,10 @@
 mkdir -p $NDKCCPATH
 WORK=GOPATH1/pkg/gomobile/android-{{.NDK}}/work
 mkdir -p $WORK/go/pkg
-cp -a $HOME/go/include $WORK/go/include
-cp -a $HOME/go/lib $WORK/go/lib
-cp -a $HOME/go/src $WORK/go/src
-ln -s $HOME/go/.git $WORK/go/.git
+cp -a $GOROOT/include $WORK/go/include
+cp -a $GOROOT/lib $WORK/go/lib
+cp -a $GOROOT/src $WORK/go/src
+ln -s $GOROOT/.git $WORK/go/.git
 curl -o$WORK/gomobile-{{.NDK}}-{{.GOOS}}-{{.NDKARCH}}.tar.gz https://dl.google.com/go/mobile/gomobile-{{.NDK}}-{{.GOOS}}-{{.NDKARCH}}.tar.gz
 tar xfz gomobile-{{.NDK}}-{{.GOOS}}-{{.NDKARCH}}.tar.gz
 mkdir -p $NDKCCPATH/arm/sysroot/usr
@@ -92,8 +92,8 @@
 mv $WORK/go/pkg/tool/{{.GOOS}}_{{.GOARCH}}/pack $NDKCCPATH/arm/bin/pack
 mv $WORK/go/pkg/tool/{{.GOOS}}_{{.GOARCH}}/link $NDKCCPATH/arm/bin/link
 go build -o $NDKCCPATH/arm/bin/toolexec $WORK/toolexec.go
-rm -r -f "$HOME/go/pkg/android_arm"
-mv $WORK/go/pkg/android_arm $HOME/go/pkg/android_arm
+rm -r -f "$GOROOT/pkg/android_arm"
+mv $WORK/go/pkg/android_arm $GOROOT/pkg/android_arm
 go version > GOPATH1/pkg/gomobile/version
 rm -r -f "$WORK"
 `))