Add more generic support for java targets bundling multiple directories

build/android/ant/chromium-jars.xml

 <!--
   Copyright (c) 2012 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.
 -->
 <project name="chromium-jars" default="dist">
   <!--
     Common ant build file for for chromium_*.jars.
     For creating a new chromium_*.jar :
     1. Use build/java.gypi action.
     The jar will be created as chromium_${PACKAGE_NAME} in
     ${PRODUCT_DIR}/lib.java.
   -->
   <description>
     Building ${PROJECT_NAME}/ java source code with ant.
   </description>
 
   <import file="common.xml"/>
 
   <path id="javac.custom.classpath">
     <filelist files="${INPUT_JARS_PATHS}"/>
     <pathelement location="${ANDROID_SDK}/android.jar"/>
   </path>
 
   <path id="javac.srcdirs.additional">
     <filelist files="${ADDITIONAL_SRC_DIRS}"/>
+    <filelist files="${GENERATED_SRC_DIRS}"/>
   </path>
 
   <property-value
     name="javac.srcdir"
     value="src:${toString:javac.srcdirs.additional}"
   />
 
   <property-location
     name="dest.dir"
     location="${PRODUCT_DIR}/java/${PACKAGE_NAME}"
@@ skipping 50 matching lines @@
          be rebuilt in future builds.
     -->
     <touch file="${lib.java.dir}/chromium_${PACKAGE_NAME}.jar"/>
   </target>
 
   <target name="clean" description="clean up">
     <!-- Delete the appropriate directory trees -->
     <delete dir="${dest.dir}"/>
   </target>
 </project>