Fix string escaping on OS X paths

chrome/common/extensions/docs/examples/api/nativeMessaging/host/install_host.sh

 #!/bin/sh
 # Copyright 2013 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.
 
 set -e
 
 DIR="$( cd "$( dirname "$0" )" && pwd )"
 if [ $(uname -s) == 'Darwin' ]; then
   if [ "$(whoami)" == "root" ]; then
     TARGET_DIR="/Library/Google/Chrome/NativeMessagingHosts"
   else
-    TARGET_DIR=\
-        "$HOME/Library/Application Support/Google/Chrome/NativeMessagingHosts"
+    TARGET_DIR="
+        $HOME/Library/Application Support/Google/Chrome/NativeMessagingHosts"

[Sergey Ulanov, 2014/09/20 17:50:04]

This adds spaces in TARGET_DIR, do I don't think you need this change 

[Patrick Kettner, 2014/09/20 18:00:57]

It does add a space, however that space doesn't change anything since all of the
commands ignore multiple sequential spaces.  

The change was required because the newline followed by the leading spaces on
the script cause the shell to try and execute the path. At least on my zsh (zsh
5.0.6 (x86_64-apple-darwin14.0.0)) and bash (GNU bash, version 4.3.24(1)-release
(x86_64-apple-darwin14.0.0))

An alternative would be to scrunch line 14 against the far left with no leading
spaces, but that seemed an uglier fix.

   fi
 else
   if [ "$(whoami)" == "root" ]; then
     TARGET_DIR="/etc/opt/chrome/native-messaging-hosts"
   else
     TARGET_DIR="$HOME/.config/google-chrome/NativeMessagingHosts"
   fi
 fi
 
 HOST_NAME=com.google.chrome.example.echo
 
 # Create directory to store native messaging host.
-mkdir -p $TARGET_DIR
+mkdir -p "$TARGET_DIR"
 
 # Copy native messaging host manifest.
-cp $DIR/$HOST_NAME.json $TARGET_DIR
+cp $DIR/$HOST_NAME.json "$TARGET_DIR"
 
 # Update host path in the manifest.
 HOST_PATH=$DIR/native-messaging-example-host
 ESCAPED_HOST_PATH=${HOST_PATH////\\/}
-sed -i -e "s/HOST_PATH/$ESCAPED_HOST_PATH/" $TARGET_DIR/$HOST_NAME.json
+sed -i -e "s/HOST_PATH/$ESCAPED_HOST_PATH/" "$TARGET_DIR/$HOST_NAME.json"
 
 # Set permissions for the manifest so that all users can read it.
-chmod o+r $TARGET_DIR/$HOST_NAME.json
+chmod o+r "$TARGET_DIR/$HOST_NAME.json"
 
 echo Native messaging host $HOST_NAME has been installed.