Fix the timestamp generation for webrtc native log.

chrome/renderer/media/chrome_webrtc_log_message_delegate.cc

 // Copyright 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.
 
 #include "chrome/renderer/media/chrome_webrtc_log_message_delegate.h"
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "chrome/common/partial_circular_buffer.h"
-#include "chrome/renderer/media/webrtc_logging_message_filter.h"
 
 ChromeWebRtcLogMessageDelegate::ChromeWebRtcLogMessageDelegate(
     const scoped_refptr<base::MessageLoopProxy>& io_message_loop,
     WebRtcLoggingMessageFilter* message_filter)
     : io_message_loop_(io_message_loop),
       logging_started_(false),
       message_filter_(message_filter) {
   content::InitWebRtcLoggingDelegate(this);
 }
 
 ChromeWebRtcLogMessageDelegate::~ChromeWebRtcLogMessageDelegate() {
   DCHECK(CalledOnValidThread());
 }
 
 void ChromeWebRtcLogMessageDelegate::LogMessage(const std::string& message) {
+  WebRtcLoggingMessage message_with_timestamp;
+  message_with_timestamp.timestamp_ms = base::Time::Now().ToInternalValue() /
+      base::Time::kMicrosecondsPerMillisecond;
+  message_with_timestamp.message = message;
+
   io_message_loop_->PostTask(
       FROM_HERE, base::Bind(
           &ChromeWebRtcLogMessageDelegate::LogMessageOnIOThread,
           base::Unretained(this),
-          message));
+          message_with_timestamp));
 }
 
 void ChromeWebRtcLogMessageDelegate::LogMessageOnIOThread(
-    const std::string& message) {
+    const WebRtcLoggingMessage& message) {
   DCHECK(CalledOnValidThread());
+
   if (logging_started_ && message_filter_) {
     if (!log_buffer_.empty()) {
       // A delayed task has already been posted for sending the buffer contents.
       // Just add the message to the buffer.
-      log_buffer_ += "\n" + message;
+      log_buffer_.push_back(message);
+      return;
+    }
+
+    log_buffer_.push_back(message);
+
+    if (base::TimeTicks::Now() - last_log_buffer_send_ >
+        base::TimeDelta::FromMilliseconds(100)) {
+      SendLogBuffer();
     } else {
-      if (base::TimeTicks::Now() - last_log_buffer_send_ >
-          base::TimeDelta::FromMilliseconds(100)) {
-        log_buffer_ = message;
-        SendLogBuffer();
-      } else {
-        log_buffer_ = message;
-        io_message_loop_->PostDelayedTask(
-            FROM_HERE,
-            base::Bind(&ChromeWebRtcLogMessageDelegate::SendLogBuffer,
-                       base::Unretained(this)),
-            base::TimeDelta::FromMilliseconds(200));
-      }
+      io_message_loop_->PostDelayedTask(
+          FROM_HERE,
+          base::Bind(&ChromeWebRtcLogMessageDelegate::SendLogBuffer,
+                     base::Unretained(this)),
+          base::TimeDelta::FromMilliseconds(200));

[dcheng, 2014/04/01 23:35:19]

Out of scope for this patch, but is base::Unretained() here actually OK? As a
reviewer, I don't see any guarantee that there will be no pending tasks
referencing this object when it is destroyed.

In fact, I see there's http://crbug.com/337432 filed about this.

     }
   }
 }
 
 void ChromeWebRtcLogMessageDelegate::OnFilterRemoved() {
   DCHECK(CalledOnValidThread());
   message_filter_ = NULL;
 }
 
 void ChromeWebRtcLogMessageDelegate::OnStartLogging() {
   DCHECK(CalledOnValidThread());
   logging_started_ = true;
   content::InitWebRtcLogging();
 }
 
 void ChromeWebRtcLogMessageDelegate::OnStopLogging() {
   DCHECK(CalledOnValidThread());
   if (!log_buffer_.empty())
     SendLogBuffer();
   if (message_filter_)
     message_filter_->LoggingStopped();
   logging_started_ = false;
 }
 
 void ChromeWebRtcLogMessageDelegate::SendLogBuffer() {
   DCHECK(CalledOnValidThread());
   if (logging_started_ && message_filter_) {

[dcheng, 2014/04/01 23:35:19]

Nit: This message_filter_ check is not actually needed, since you never call
this function if message_filter_ is null.

[jiayl, 2014/04/02 00:38:06]

It can be null if SendLogBuffer is called from the delayed task:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/renderer/me...

-    message_filter_->AddLogMessage(log_buffer_);
+    message_filter_->AddLogMessages(log_buffer_);
     last_log_buffer_send_ = base::TimeTicks::Now();
   }
   log_buffer_.clear();
 }