Introduce ExclusiveOwnershipPointer.

native/jni/Android.mk

...ve/jni/com_android_inputmethod_latin_BinaryDictionary.cpp

native/jni/src/suggest/core/dictionary/dictionary.cpp

native/jni/src/suggest/core/dictionary/dictionary.h

...est/core/policy/dictionary_structure_with_buffer_policy.h

...cture/dictionary_structure_with_buffer_policy_factory.cpp

...ructure/dictionary_structure_with_buffer_policy_factory.h

...policyimpl/dictionary/structure/v2/patricia_trie_policy.h

.../dictionary/structure/v3/dynamic_patricia_trie_policy.cpp

...pl/dictionary/structure/v3/dynamic_patricia_trie_policy.h

...rc/suggest/policyimpl/dictionary/utils/mmapped_buffer.cpp

.../src/suggest/policyimpl/dictionary/utils/mmapped_buffer.h

native/jni/src/utils/exclusive_ownership_pointer.h