Increase default memory for newly created web apps.

Issue: 9213

Change-Id: Icb911b334112266fdccd9f8d9cbb9187eb61ef4c

user/src/com/google/gwt/user/tools/templates/ant/build.xmlsrc

diff --git a/user/src/com/google/gwt/user/tools/templates/ant/build.xmlsrc b/user/src/com/google/gwt/user/tools/templates/ant/build.xmlsrc
index cc54727..d1dac99 100644
--- a/user/src/com/google/gwt/user/tools/templates/ant/build.xmlsrc
+++ b/user/src/com/google/gwt/user/tools/templates/ant/build.xmlsrc
@@ -37,7 +37,7 @@
   </target>
 
   <target name="gwtc" depends="javac" description="GWT compile to JavaScript (production mode)">
-    <java failonerror="true" fork="true" classname="@compileClass" maxmemory="256m">
+    <java failonerror="true" fork="true" classname="@compileClass" maxmemory="512m">
       <classpath>
         <pathelement location="@srcFolder"/>
         <path refid="project.class.path"/>