Measure IPC latency for audio...

chrome/renderer/audio_message_filter.cc

Index: chrome/renderer/audio_message_filter.cc
===================================================================
--- chrome/renderer/audio_message_filter.cc	(revision 14824)
+++ chrome/renderer/audio_message_filter.cc	(working copy)
@@ -2,10 +2,28 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/histogram.h"
 #include "base/message_loop.h"
+#include "chrome/common/ipc_logging.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/renderer/audio_message_filter.h"
 
+namespace {
+
+void RecordReceiveLatency(base::TimeDelta latency) {
+  static ThreadSafeHistogram histogram("Audio.IPC_Renderer_ReceiveLatency",
+                                       1, 500, 100);
+  histogram.AddTime(latency);
+}
+
+void RecordProcessTime(base::TimeDelta latency) {
+  static ThreadSafeHistogram histogram("Audio.IPC_Renderer_ProcessTime",
+                                       1, 100, 100);
+  histogram.AddTime(latency);
+}
+
+}  // namespace
+
 AudioMessageFilter::AudioMessageFilter(int32 route_id)
     : channel_(NULL),
       route_id_(route_id),
@@ -55,14 +73,31 @@
   channel_ = NULL;
 }
 
-void AudioMessageFilter::OnRequestPacket(int stream_id) {
+void AudioMessageFilter::OnRequestPacket(const IPC::Message& msg,
+                                         int stream_id) {
   Delegate* delegate = delegates_.Lookup(stream_id);
   if (!delegate) {
     DLOG(WARNING) << "Got audio packet request for a non-existent or removed"
         " audio renderer.";
     return;
   }
+
+#ifdef IPC_MESSAGE_LOG_ENABLED
+  IPC::Logging* logger = IPC::Logging::current();
+  if (logger->Enabled()) {
+    RecordReceiveLatency(base::Time::FromInternalValue(msg.received_time()) -
+                         base::Time::FromInternalValue(msg.sent_time()));
+  }
+#endif
+
   delegate->OnRequestPacket();
+
+#ifdef IPC_MESSAGE_LOG_ENABLED
+  if (logger->Enabled()) {
+    RecordProcessTime(base::Time::Now() -
+                      base::Time::FromInternalValue(msg.received_time()));
+  }
+#endif
 }
 
 void AudioMessageFilter::OnStreamCreated(int stream_id,