Adds the ability to load JSON log files to about:net-internals.

chrome/browser/net/net_log_logger.h

Index: chrome/browser/net/net_log_logger.h
===================================================================
--- chrome/browser/net/net_log_logger.h	(revision 70414)
+++ chrome/browser/net/net_log_logger.h	(working copy)
@@ -6,14 +6,23 @@
 #define CHROME_BROWSER_NET_NET_LOG_LOGGER_H_
 #pragma once
 
+#include "base/scoped_handle.h"
 #include "chrome/browser/net/chrome_net_log.h"
 
+class FilePath;
+
 // NetLogLogger watches the NetLog event stream, and sends all entries to
-// VLOG(1).  This is to debug errors that prevent getting to the
-// about:net-internals page.
+// VLOG(1) or a path specified on creation.  This is to debug errors that
+// prevent getting to the about:net-internals page.
+//
+// Relies on ChromeNetLog only calling an Observer once at a time for
+// thread-safety.
 class NetLogLogger : public ChromeNetLog::ThreadSafeObserver {
  public:
-  NetLogLogger();
+  // If |log_path| is empty or file creation fails, writes to VLOG(1) using
+  // pretty formatting.  Otherwise, writes to |log_path| using one line per
+  // entry, for easy parsing.
+  explicit NetLogLogger(const FilePath &log_path);
   ~NetLogLogger();
 
   // ThreadSafeObserver implementation:
@@ -24,6 +33,8 @@
                           net::NetLog::EventParameters* params);
 
  private:
+  ScopedStdioHandle file_;
+
   DISALLOW_COPY_AND_ASSIGN(NetLogLogger);
 };