add option to wait longer for ShardingTest.prototype.awaitBalance

Author: erh

src/mongo/shell/shardingtest.js

@@ -822,7 +822,8 @@ ShardingTest.prototype.chunkDiff = function( collName , dbName ){
 // Waits up to one minute for the difference in chunks between the most loaded shard and least
 // loaded shard to be 0 or 1, indicating that the collection is well balanced.
 // This should only be called after creating a big enough chunk difference to trigger balancing.
-ShardingTest.prototype.awaitBalance = function( collName , dbName ) {
+ShardingTest.prototype.awaitBalance = function( collName , dbName , timeToWait ) {
+    timeToWait = timeToWait || 60000;
     var shardingTest = this;
     assert.soon( function() {
         var x = shardingTest.chunkDiff( collName , dbName );