Uses Hash values for sparse histograms for InputMethod.ID statistics.

chrome/browser/chromeos/input_method/input_method_manager_impl.h

Index: chrome/browser/chromeos/input_method/input_method_manager_impl.h
diff --git a/chrome/browser/chromeos/input_method/input_method_manager_impl.h b/chrome/browser/chromeos/input_method/input_method_manager_impl.h
index 3c5b7efb43eb5ae487fc3c8b3b3812bc08a3b3ac..f0f7a2d2885e418fe0a53cb136d780315054d1a9 100644
--- a/chrome/browser/chromeos/input_method/input_method_manager_impl.h
+++ b/chrome/browser/chromeos/input_method/input_method_manager_impl.h
@@ -258,16 +258,6 @@ class InputMethodManagerImpl : public InputMethodManager,
   typedef std::map<Profile*, EngineMap, ProfileCompare> ProfileEngineMap;
   ProfileEngineMap engine_map_;
 
-  // The map from input method id to the input method stat id.
-  // The stat id has the format: <category#><first char after prefix><index>
-  // For example, Chinese Simplified Pinyin IME has the stat id:
-  //   2,'p',1 -> 211201
-  //   2 means it in INPUT_METHOD_CATEGORY_ZH;
-  //   112 means the first char after prefix is 'p' of 'pinyin';
-  //   01 means it's the second pinyin as the first pinyin is for Traditional
-  //   Chinese Pinyin IME. Note "zh-hant-t-i0-pinyin" < "zh-t-i0-pinyin".
-  std::map<std::string, int> stat_id_map_;
-
   DISALLOW_COPY_AND_ASSIGN(InputMethodManagerImpl);
 };