Consolidate LanguageModelParam constructors

Change-Id: I142651d1f268456a5901da524cbe55d315f76d28
diff --git a/java/src/com/android/inputmethod/latin/utils/LanguageModelParam.java b/java/src/com/android/inputmethod/latin/utils/LanguageModelParam.java
index 847b7bb..663b6cd 100644
--- a/java/src/com/android/inputmethod/latin/utils/LanguageModelParam.java
+++ b/java/src/com/android/inputmethod/latin/utils/LanguageModelParam.java
@@ -35,16 +35,7 @@
     // Constructor for unigram. TODO: support shortcuts
     public LanguageModelParam(final String word, final int unigramProbability,
             final int timestamp) {
-        mTargetWord = word;
-        mWord0 = null;
-        mWord1 = StringUtils.toCodePointArray(word);
-        mShortcutTarget = null;
-        mUnigramProbability = unigramProbability;
-        mBigramProbability = Dictionary.NOT_A_PROBABILITY;
-        mShortcutProbability = Dictionary.NOT_A_PROBABILITY;
-        mIsNotAWord = false;
-        mIsBlacklisted = false;
-        mTimestamp = timestamp;
+        this(null /* word0 */, word, unigramProbability, Dictionary.NOT_A_PROBABILITY, timestamp);
     }
 
     // Constructor for unigram and bigram.
@@ -52,7 +43,7 @@
             final int unigramProbability, final int bigramProbability,
             final int timestamp) {
         mTargetWord = word1;
-        mWord0 = StringUtils.toCodePointArray(word0);
+        mWord0 = (word0 == null) ? null : StringUtils.toCodePointArray(word0);
         mWord1 = StringUtils.toCodePointArray(word1);
         mShortcutTarget = null;
         mUnigramProbability = unigramProbability;