Add framework for basic cr command

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

+// 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")
+}