Removing unused methods on Cache and synchronizing it since FieldAttributes contains a static instance of this type.

gson/src/main/java/com/google/gson/Cache.java

@@ -48,14 +48,4 @@ interface Cache<K, V> {
    * @return the value for the given {@code key}
    */
   V removeElement(K key);
-
-  /**
-   * Removes everything from this cache.
-   */
-  void clear();
-  
-  /**
-   * @return the number of objects in this cache
-   */
-  int size();
 }

gson/src/main/java/com/google/gson/LruCache.java

@@ -37,28 +37,18 @@ final class LruCache<K, V> extends LinkedHashMap<K, V> implements Cache<K, V> {
     this.maxCapacity = maxCapacity;
   }
 
-  public void addElement(K key, V value) {
+  public synchronized void addElement(K key, V value) {
     put(key, value);
   }
 
-  @Override
-  public void clear() {
-    super.clear();
-  }
-
-  public V getElement(K key) {
+  public synchronized V getElement(K key) {
     return get(key);
   }
 
-  public V removeElement(K key) {
+  public synchronized V removeElement(K key) {
     return remove(key);
   }
 
-  @Override
-  public int size() {
-    return super.size();
-  }
-  
   @Override
   protected boolean removeEldestEntry(Map.Entry<K, V> entry) {
     return size() > maxCapacity;