[Android] Add gyp support for multidex.

build/android/ant/apk-package.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
     Copyright (C) 2005-2008 The Android Open Source Project
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at
 
          http://www.apache.org/licenses/LICENSE-2.0
 
@@ skipping 36 matching lines @@
 
   <!-- SDK tools assume that out.packaged.file is signed and name it "...-unaligned" -->
   <property name="out.packaged.file" value="${UNSIGNED_APK_PATH}" />
 
   <property name="native.libs.absolute.dir" location="${NATIVE_LIBS_DIR}" />
 
   <!-- Intermediate files -->
   <property name="resource.package.file.name" value="${RESOURCE_PACKAGED_APK_NAME}" />
 
   <property name="intermediate.dex.file" location="${DEX_FILE_PATH}" />
+  <condition property="multidex.enabled" value="true">
+    <equals arg1="${MULTIDEX_ENABLED}" arg2="1"/>
+  </condition>
 
   <!-- Macro that enables passing a variable list of external jar files
        to ApkBuilder. -->
   <macrodef name="package-helper">
     <element name="extra-jars" optional="yes" />
     <sequential>
       <apkbuilder
           outfolder="${out.absolute.dir}"
           resourcefile="${resource.package.file.name}"
           apkfilepath="${out.packaged.file}"
           debugpackaging="${build.is.packaging.debug}"
           debugsigning="${build.is.signing.debug}"
           verbose="${verbose}"
           hascode="${HAS_CODE}"
           previousBuildType="/"
           buildType="${build.is.packaging.debug}/${build.is.signing.debug}">
-        <dex path="${intermediate.dex.file}"/>
+        <dex path="${intermediate.dex.file}" />
         <nativefolder path="${native.libs.absolute.dir}" />
         <extra-jars/>
       </apkbuilder>
     </sequential>
   </macrodef>
 
+  <macrodef name="multidex-package-helper">
+    <element name="extra-jars" optional="yes" />
+    <sequential>
+      <apkbuilder
+          outfolder="${out.absolute.dir}"
+          resourcefile="${resource.package.file.name}"
+          apkfilepath="${out.packaged.file}"
+          debugpackaging="${build.is.packaging.debug}"
+          debugsigning="${build.is.signing.debug}"
+          verbose="${verbose}"
+          hascode="false"
+          previousBuildType="/"
+          buildType="${build.is.packaging.debug}/${build.is.signing.debug}">
+        <zip path="${intermediate.dex.file}" />
+        <nativefolder path="${native.libs.absolute.dir}" />
+        <extra-jars/>
+      </apkbuilder>
+    </sequential>
+  </macrodef>
 
   <!-- Packages the application. -->
   <target name="-package">
     <if condition="${emma.enabled}">
       <then>
         <package-helper>
           <extra-jars>
             <jarfile path="${emma.device.jar}" />
           </extra-jars>
         </package-helper>
       </then>
       <else>
-        <package-helper />
+        <if condition="${multidex.enabled}">
+          <then>
+            <echo message="multidex enabled" />
+            <multidex-package-helper />
+          </then>
+          <else>
+            <echo message="multidex disabled" />
+            <package-helper />
+          </else>
+        </if>
       </else>
     </if>
   </target>
 </project>