[cipd] Enable subdirs functionality.

cipd/client/cipd/common/common.go

Index: cipd/client/cipd/common/common.go
diff --git a/cipd/client/cipd/common/common.go b/cipd/client/cipd/common/common.go
index 0aee744b9905a2bd248d2bb737a3e974b681208f..11bcd48b8a5cd8898688cc17677d199acc54bbbe 100644
--- a/cipd/client/cipd/common/common.go
+++ b/cipd/client/cipd/common/common.go
@@ -6,7 +6,6 @@
 package common
 
 import (
-	"errors"
 	"fmt"
 	"path"
 	"regexp"
@@ -250,21 +249,6 @@ func (p PinSliceBySubdir) Validate() error {
 	return nil
 }
 
-// ErrSubdirsNotYetSupported is a transitionary error which indicates that the
-// invoked method does not yet work with sudbir values other than "".
-var ErrSubdirsNotYetSupported = errors.New(`subdirs other than "" not currently supported`)
-
-// AssertOnlyDefaultSubdir is a transitionary method which returns an error if
-// p contains subdirs other than "".
-func (p PinSliceBySubdir) AssertOnlyDefaultSubdir() error {
-	if _, ok := p[""]; ok && len(p) > 1 {
-		return ErrSubdirsNotYetSupported
-	} else if !ok && len(p) > 0 {
-		return ErrSubdirsNotYetSupported
-	}
-	return nil
-}
-
 // ToMap converts this to a PinMapBySubdir
 func (p PinSliceBySubdir) ToMap() PinMapBySubdir {
 	ret := make(PinMapBySubdir, len(p))