BlameCache: Add getCache() method to match other caches

Change-Id: Ib643d6ca12cf5a7a3139d16972ba7ca5919dd61b

gitiles-servlet/src/main/java/com/google/gitiles/BlameCache.java

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/BlameCache.java b/gitiles-servlet/src/main/java/com/google/gitiles/BlameCache.java
index f330839..b996048 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/BlameCache.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/BlameCache.java
@@ -116,6 +116,10 @@
     this(newBuilder());
   }
 
+  public LoadingCache<?, ?> getCache() {
+    return cache;
+  }
+
   public BlameCache(CacheBuilder<Object, Object> builder) {
     this.cache = builder.weigher(new Weigher<Key, List<BlameCache.Region>>() {
       @Override