rename PerformanceServerTiming members to conform with 'Blink Rename'

third_party/WebKit/Source/core/timing/PerformanceServerTiming.h

Index: third_party/WebKit/Source/core/timing/PerformanceServerTiming.h
diff --git a/third_party/WebKit/Source/core/timing/PerformanceServerTiming.h b/third_party/WebKit/Source/core/timing/PerformanceServerTiming.h
index a4d211be8f9394680db92d6d9e3d59d9f06cabbe..814dfe415d32e1281ead143440b8e15a6da5cfec 100644
--- a/third_party/WebKit/Source/core/timing/PerformanceServerTiming.h
+++ b/third_party/WebKit/Source/core/timing/PerformanceServerTiming.h
@@ -34,8 +34,8 @@ class CORE_EXPORT PerformanceServerTiming : public PerformanceEntry {
                           double duration,
                           const String& description);
 
-  const String m_metric;
-  const String m_description;
+  const String metric_;
+  const String description_;
 };
 
 }  // namespace blink