Bug: 13756409

[Category diff]
+1      27
-1       0
+2       0
-2       0
+3       0
-3       1
+4      11
-4       0
+5      51
-5       0
+6       0
-6      38
+7       0
-7      50

[Weighted category diff]
+1      28
-1       0
+2       0
-2       0
+3       0
-3       1
+4      11
-4       0
+5      51
-5       0
+6       0
-6      39
+7       0
-7      50

show diff for ./en_user_log_phones_2011_08.csv
+1       4
+4       5
+5       7
-6       9
-7       7

The increase of false positives comes from the spaceless
typing test cases that are synthetic data.

Change-Id: I4ea77aa56ebfaa5518c71107169e1d2332de6327