Fix bug 6558006: SystemUI native heap is huge. Fix memory leak
Fix bug 6558006: SystemUI native heap is huge. Fix memory leak

TextLayoutCache was leaking HB_Face objects, not freeing them when
purging the mCachedHBFaces cache. More full analysis is in the bug.

Change-Id: Ie5cd8b00c36b9d31963183c601cde49cbb73fafb

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base