C++ readability review from original change https://chromiumcodereview.appspot.com/14263024/

chrome/test/chromedriver/chrome/performance_logger.h

Index: chrome/test/chromedriver/chrome/performance_logger.h
diff --git a/chrome/test/chromedriver/chrome/performance_logger.h b/chrome/test/chromedriver/chrome/performance_logger.h
index 93306b8ca72123468d3bc64349b3b0671b032b17..b9cc8a14104a633bd4ecccbe9bd78d302934f8e9 100644
--- a/chrome/test/chromedriver/chrome/performance_logger.h
+++ b/chrome/test/chromedriver/chrome/performance_logger.h
@@ -20,15 +20,19 @@ class Log;
 // }
 class PerformanceLogger : public DevToolsEventListener {
  public:
+  // Creates a PerformanceLogger that creates entries in the given Log object.
+  // The log is owned elsewhere and must not be null.
   explicit PerformanceLogger(Log* log);
 
+  // Enables Page,Network,Timeline events for client, which must not be null.
   virtual Status OnConnected(DevToolsClient* client) OVERRIDE;
+  // Translates an event into a log entry.
   virtual Status OnEvent(DevToolsClient* client,
                          const std::string& method,
                          const base::DictionaryValue& params) OVERRIDE;
 
  private:
-  Log* log_;
+  Log* log_;  // The log where to create entries.
 
   DISALLOW_COPY_AND_ASSIGN(PerformanceLogger);
 };