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

chrome/test/chromedriver/chrome/performance_logger.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_TEST_CHROMEDRIVER_CHROME_PERFORMANCE_LOGGER_H_
 #define CHROME_TEST_CHROMEDRIVER_CHROME_PERFORMANCE_LOGGER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "chrome/test/chromedriver/chrome/devtools_event_listener.h"
 
 class Log;
 
 // Translates DevTools profiler events into Log messages with info level.
 //
 // The message is a JSON string of the following structure:
 // {
 //    "webview": <originating WebView ID>,
 //    "message": { "method": "...", "params": { ... }}  // DevTools message.
 // }
 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);
 };
 
 #endif  // CHROME_TEST_CHROMEDRIVER_CHROME_PERFORMANCE_LOGGER_H_