Start to use historical info.

Bug: 11073222
Change-Id: I232d41bec5df7952856b5ba4765977707c39b94a
diff --git a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
index 555c71b..93ccc62 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
@@ -368,6 +368,7 @@
         // and latinime::HeaderReadWriteUtils.
         public static final String SUPPORTS_DYNAMIC_UPDATE_ATTRIBUTE = "SUPPORTS_DYNAMIC_UPDATE";
         public static final String USES_FORGETTING_CURVE_ATTRIBUTE = "USES_FORGETTING_CURVE";
+        public static final String HAS_HISTORICAL_INFO_ATTRIBUTE = "HAS_HISTORICAL_INFO";
         public static final String ATTRIBUTE_VALUE_TRUE = "1";
 
         public static final String DICTIONARY_VERSION_ATTRIBUTE = "version";
diff --git a/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java b/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java
index f4b7d6e..529ddc2 100644
--- a/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java
+++ b/java/src/com/android/inputmethod/latin/personalization/DecayingExpandableBinaryDictionaryBase.java
@@ -94,6 +94,8 @@
                 FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
         attributeMap.put(FormatSpec.FileHeader.USES_FORGETTING_CURVE_ATTRIBUTE,
                 FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
+        attributeMap.put(FormatSpec.FileHeader.HAS_HISTORICAL_INFO_ATTRIBUTE,
+                FormatSpec.FileHeader.ATTRIBUTE_VALUE_TRUE);
         attributeMap.put(FormatSpec.FileHeader.DICTIONARY_ID_ATTRIBUTE, mFileName);
         attributeMap.put(FormatSpec.FileHeader.DICTIONARY_LOCALE_ATTRIBUTE, mLocale.toString());
         attributeMap.put(FormatSpec.FileHeader.DICTIONARY_VERSION_ATTRIBUTE,