Fixes OOM bitmap crash.

Change-Id: Ied0293b7f1dbfe16c3517dbb9e2b19c8030d31a5
diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index c3be486..c71234b 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -2465,7 +2465,10 @@
 
         Canvas canvas = new Canvas(sThumbnailBitmap);
         canvas.drawBitmap(viewportBitmap, srcRect, dstRect, new Paint(Paint.FILTER_BITMAP_FLAG));
-
+        if (viewportBitmap != null) {
+            viewportBitmap.recycle();
+            viewportBitmap = null;
+        }
         return sThumbnailBitmap;
     }