Add region tags to firebase sample.

appengine/firebase-tictactoe/src/main/java/com/example/appengine/firetactoe/Game.java

@@ -104,7 +104,7 @@ public void setMoveX(boolean moveX) {
     this.moveX = moveX;
   }
 
-  //[START send_updates]
+  // [START send_updates]
   public String getChannelKey(String userId) {
     return userId + id;
   }
@@ -130,7 +130,7 @@ public void sendUpdateToClients()
     sendUpdateToUser(userX);
     sendUpdateToUser(userO);
   }
-  //[END send_updates]
+  // [END send_updates]
 
   public void checkWin() {
     final Pattern[] wins;
@@ -152,7 +152,6 @@ public void checkWin() {
     }
   }
 
-  //[START make_move]
   public boolean makeMove(int position, String userId) {
     String currentMovePlayer;
     char value;
@@ -181,5 +180,4 @@ public boolean makeMove(int position, String userId) {
 
     return false;
   }
-  //[END make_move]
 }

appengine/firebase-tictactoe/src/main/java/com/example/appengine/firetactoe/TicTacToeServlet.java

@@ -88,6 +88,7 @@ public void doGet(HttpServletRequest request, HttpServletResponse response)
 
     // 3. Inject a secure token into the client, so it can get game updates
 
+    // [START pass_token]
     // The 'Game' object exposes a method which creates a unique string based on the game's key
     // and the user's id.
     String token = FirebaseChannel.getInstance().createFirebaseToken(game, userId);
@@ -100,5 +101,6 @@ public void doGet(HttpServletRequest request, HttpServletResponse response)
     request.setAttribute("initial_message", new Gson().toJson(game));
     request.setAttribute("game_link", getGameUriWithGameParam(request, gameKey));
     request.getRequestDispatcher("/WEB-INF/view/index.jsp").forward(request, response);
+    // [END pass_token]
   }
 }

appengine/firebase-tictactoe/src/main/webapp/static/main.js

@@ -132,18 +132,22 @@ function initGame(gameKey, me, token, channelId, initialMessage) {
    * finally, it calls onOpened() to let the server know it is ready to receive messages
    */
   function openChannel() {
+    // [START auth_login]
     // sign into Firebase with the token passed from the server
     firebase.auth().signInWithCustomToken(token).catch(function(error) {
       console.log('Login Failed!', error.code);
       console.log('Error message: ', error.message);
     });
+    // [END auth_login]
 
+    // [START add_listener]
     // setup a database reference at path /channels/channelId
     channel = firebase.database().ref('channels/' + channelId);
     // add a listener to the path that fires any time the value of the data changes
     channel.on('value', function(data) {
       onMessage(data.val());
     });
+    // [END add_listener]
     onOpened();
     // let the server know that the channel is open
   }