Rename all of experiments_helper to variations_helper, including files, namespaces, and various function names.

TEST=none
BUG=none
Review URL: https://chromiumcodereview.appspot.com/10795060

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151357 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/metrics/metrics_log.h b/chrome/browser/metrics/metrics_log.h
index 89e2e7b..4c5a72c 100644
--- a/chrome/browser/metrics/metrics_log.h
+++ b/chrome/browser/metrics/metrics_log.h
@@ -28,7 +28,7 @@
 struct ProcessDataSnapshot;
 }
 
-namespace experiments_helper {
+namespace chrome_variations {
 struct SelectedGroupId;
 }
 
@@ -132,7 +132,7 @@
   // Fills |field_trial_ids| with the list of initialized field trials name and
   // group ids.
   virtual void GetFieldTrialIds(
-    std::vector<experiments_helper::SelectedGroupId>* field_trial_ids) const;
+    std::vector<chrome_variations::SelectedGroupId>* field_trial_ids) const;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(MetricsLogTest, ChromeOSStabilityData);