Quit recording LastUserHistoryWriteTime.

...android/inputmethod/latin/ExpandableBinaryDictionary.java

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

...rsonalization/DecayingExpandableBinaryDictionaryBase.java

...thod/latin/personalization/PersonalizationDictionary.java

...utmethod/latin/personalization/PersonalizationHelper.java

.../personalization/PersonalizationPredictionDictionary.java

...utmethod/latin/personalization/UserHistoryDictionary.java

.../src/com/android/inputmethod/latin/settings/Settings.java

.../src/com/android/inputmethod/latin/utils/LocaleUtils.java

...hod/latin/personalization/UserHistoryDictionaryTests.java