Small memory cleanups.

SeleniumGridExtras/src/main/java/com/groupon/seleniumgridextras/grid/SessionTracker.java

@@ -1,15 +1,27 @@
 package com.groupon.seleniumgridextras.grid;
 
+import com.groupon.seleniumgridextras.config.*;
+
 import java.util.LinkedList;
 import java.util.List;
 
 public class SessionTracker {
 
-    List<String> sessionsRecorded = new LinkedList<String>();
+    LinkedList<String> sessionsRecorded = new LinkedList<String>();
 
 
     public void startSession(String session) {
         sessionsRecorded.add(session);
+
+        // videos to keep, and sessions to keep track of
+        int videosToKeep
+            = RuntimeConfig.getConfig().getVideoRecording().getVideosToKeep();
+        if (videosToKeep > 0
+            && sessionsRecorded.size() > videosToKeep)
+        {
+            // then forget the first session
+            sessionsRecorded.remove();
+        }
     }
 
     public List<String> getSessions() {

SeleniumGridExtras/src/main/java/com/groupon/seleniumgridextras/utilities/threads/video/VideoRecorderCallable.java

@@ -260,7 +260,9 @@ public static BufferedImage convertToType(BufferedImage sourceImage,
         else {
             image = new BufferedImage(sourceImage.getWidth(),
                     sourceImage.getHeight(), targetType);
-            image.getGraphics().drawImage(sourceImage, 0, 0, null);
+            Graphics g = image.getGraphics();
+            g.drawImage(sourceImage, 0, 0, null);
+            g.dispose();
         }
 
         return image;

SeleniumGridExtras/src/main/java/com/groupon/seleniumgridextras/videorecording/ImageProcessor.java

@@ -82,6 +82,7 @@ public static BufferedImage createTitleFrame(Dimension dimension, int imageType,
     g.setFont(new Font("TimesRoman", Font.PLAIN, 14));
     g.drawString("" + line2, firstLineX, secondLineY);
     g.drawString("" + line3, firstLineX, thirdLineY);
+    g.dispose();
 
     return image;
   }