Revert 157168 - Add guards to metric values; erase bad events/metrics from db

chrome/browser/performance_monitor/database.h

Index: chrome/browser/performance_monitor/database.h
===================================================================
--- chrome/browser/performance_monitor/database.h	(revision 157181)
+++ chrome/browser/performance_monitor/database.h	(working copy)
@@ -31,7 +31,6 @@
 };
 
 class KeyBuilder;
-class DatabaseTestHelper;
 
 // The class supporting all performance monitor storage. This class wraps
 // multiple leveldb::DB objects. All methods must be called from a background
@@ -153,10 +152,12 @@
   }
 
   // Add a metric instance to the database.
-  bool AddMetric(const std::string& activity, const Metric& metric);
+  bool AddMetric(const std::string& activity,
+                 MetricType metric_type,
+                 const std::string& value);
 
-  bool AddMetric(const Metric& metric) {
-    return AddMetric(kProcessChromeAggregate, metric);
+  bool AddMetric(MetricType metric_type, const std::string& value) {
+    return AddMetric(kProcessChromeAggregate, metric_type, value);
   }
 
   // Get the metrics that are active for the given process between |start|
@@ -235,7 +236,8 @@
   }
 
  private:
-  friend class DatabaseTestHelper;
+  FRIEND_TEST_ALL_PREFIXES(PerformanceMonitorDatabaseSetupTest, OpenClose);
+  FRIEND_TEST_ALL_PREFIXES(PerformanceMonitorDatabaseSetupTest, ActiveInterval);
 
   typedef std::map<std::string, std::string> RecentMap;
   typedef std::map<std::string, double> MaxValueMap;