logd: optimize statistics

- Go back to basic requirements
- Simplify
- use hash tables to minimize memory impact

Bug: 19608965
Change-Id: If7becb34354d6415e5c387ecea7d4109a15259c8
diff --git a/logd/LogWhiteBlackList.h b/logd/LogWhiteBlackList.h
index 769d651..5f60801 100644
--- a/logd/LogWhiteBlackList.h
+++ b/logd/LogWhiteBlackList.h
@@ -61,7 +61,9 @@
     int init(char *str);
 
     bool naughty(LogBufferElement *element);
+    bool naughty(void) { return !mNaughty.empty(); }
     bool nice(LogBufferElement *element);
+    bool nice(void) { return !mNice.empty(); }
     bool worstUidEnabled() const { return mWorstUidEnabled; }
 
     // *strp is malloc'd, use free to release