Add framework for basic cr command

go/src/infra/tools/cr/cmd/root.go

Index: go/src/infra/tools/cr/cmd/root.go
diff --git a/go/src/infra/tools/cr/cmd/root.go b/go/src/infra/tools/cr/cmd/root.go
new file mode 100644
index 0000000000000000000000000000000000000000..c79e1655f8c465c0a17912f443d4d0ca1e85815d
--- /dev/null
+++ b/go/src/infra/tools/cr/cmd/root.go
@@ -0,0 +1,40 @@
+// Copyright 2016 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.
+
+/*
+Root command of the SDK; does most of the heavy lifting.
+*/
+
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+// RootCmd is the root of the command tree. All subcommands attach to this one.
+// Also defines some persistent flags which are available to all subcommands.
+// Does not have a top-level Run function; instead just prints Usage.
+var RootCmd = &cobra.Command{
+	Use:   "cr",
+	Short: "Entry point and module manager for the Chromium command-line SDK",
+	Long: `Entry point and module manager for the Chromium command-line SDK.
+
+Run "cr help", "cr help [command]", or "cr [command] --help" for documentation.`,
+}
+
+// Execute crawls the tree of commands (starting at RootCmd) to find the
+// appropriate function to execute. Prints usage is none is found.
+func Execute() {
+	if err := RootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(-1)
+	}
+}
+
+func init() {
+	RootCmd.PersistentFlags().BoolP("verbose", "v", false, "Turn on verbose logging")
+}