add capacity to FusionDictionaryBufferInterface.

bug: 6669677

Change-Id: I4627093811a19c46ce13fe351d1db63cbd78cf4a

java/src/com/android/inputmethod/latin/UserHistoryDictIOUtils.java

@@ -100,6 +100,11 @@ public class UserHistoryDictIOUtils {
 
         @Override
         public int limit() {
+            return mBuffer.length - 1;
+        }
+
+        @Override
+        public int capacity() {
             return mBuffer.length;
         }
     }

java/src/com/android/inputmethod/latin/makedict/BinaryDictInputOutput.java

@@ -63,6 +63,7 @@ public class BinaryDictInputOutput {
         public void position(int newPosition);
         public void put(final byte b);
         public int limit();
+        public int capacity();
     }
 
     public static final class ByteBufferWrapper implements FusionDictionaryBufferInterface {
@@ -112,6 +113,11 @@ public class BinaryDictInputOutput {
         public int limit() {
             return mBuffer.limit();
         }
+
+        @Override
+        public int capacity() {
+            return mBuffer.capacity();
+        }
     }
 
     /**