Enable NeedsBraces check and fix some checkstyle issues.

tools/android/checkstyle/chromium-style-5.0.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
 
 <!--
   See installation instructions: https://sites.google.com/a/chromium.org/dev/checkstyle
 -->
 <module name="Checker">
   <property name="severity" value="warning"/>
   <property name="charset" value="UTF-8"/>
   <module name="TreeWalker">
@@ skipping 83 matching lines @@
       <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
       <property name="max" value="100"/>
     </module>
     <module name="LeftCurly">
       <property name="severity" value="error"/>
     </module>
     <module name="RightCurly">
       <property name="severity" value="error"/>
     </module>
     <module name="NeedBraces">
-      <property name="severity" value="info"/>
-      <property name="tokens" value="LITERAL_FOR, LITERAL_WHILE, LITERAL_DO"/>
+      <message key="needBraces" value="if, for, while, and do require curly braces unless they are single-line statements."/>
+      <property name="severity" value="error"/>
+      <property name="tokens" value="LITERAL_FOR, LITERAL_WHILE, LITERAL_DO, LITERAL_IF"/>
+      <property name="allowSingleLineStatement" value="true"/>
     </module>
     <module name="EmptyBlock">
       <property name="severity" value="error"/>
       <property name="option" value="text"/>
       <metadata name="altname" value="EmptyCatchBlock"/>
     </module>
     <module name="UpperEll">
       <property name="severity" value="error"/>
     </module>
     <module name="FallThrough">
@@ skipping 87 matching lines @@
   <module name="RegexpSingleline">
     <property name="severity" value="error"/>
     <property name="format" value="[ \t]+$"/>
     <property name="message" value="Trailing whitespace"/>
     </module>
   <module name="RegexpHeader">
     <property name="severity" value="error"/>
     <property name="header" value="^// Copyright 20\d\d The Chromium Authors. All rights reserved.$\n^// Use of this source code is governed by a BSD-style license that can be$\n^// found in the LICENSE file.$"/>
   </module>
 </module>