Rename PrevWordsInfo to NgramContext.

java/proguard.flags

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

...m/android/inputmethod/latin/ContactsBinaryDictionary.java

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

...c/com/android/inputmethod/latin/DictionaryCollection.java

.../com/android/inputmethod/latin/DictionaryFacilitator.java

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

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

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

...m/android/inputmethod/latin/ReadOnlyBinaryDictionary.java

...rc/com/android/inputmethod/latin/RichInputConnection.java

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

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

.../com/android/inputmethod/latin/inputlogic/InputLogic.java

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

...utmethod/latin/spellcheck/AndroidSpellCheckerService.java

...utmethod/latin/spellcheck/AndroidSpellCheckerSession.java

...latin/spellcheck/AndroidWordLevelSpellCheckerSession.java

...com/android/inputmethod/latin/utils/DistracterFilter.java

...s/DistracterFilterCheckingExactMatchesAndSuggestions.java