media: Plumb MediaLog to MojoVideoDecoderService.

media/mojo/common/mojo_media_log_service.cc

Index: media/mojo/common/mojo_media_log_service.cc
diff --git a/media/mojo/common/mojo_media_log_service.cc b/media/mojo/common/mojo_media_log_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..932a02e30c02b72ea442b5e85a436a430a6290d4
--- /dev/null
+++ b/media/mojo/common/mojo_media_log_service.cc
@@ -0,0 +1,37 @@
+// Copyright 2017 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 "media/mojo/common/mojo_media_log_service.h"
+
+#include <memory>
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "media/base/media_log_event.h"
+
+namespace media {
+
+MojoMediaLogService::MojoMediaLogService(media::MediaLog* media_log)
+    : media_log_(media_log) {
+  DVLOG(1) << __func__;
+  DCHECK(media_log_);
+
+  std::unique_ptr<media::MediaLogEvent> event =
+      media_log_->CreateEvent(media::MediaLogEvent::WEBMEDIAPLAYER_CREATED);
+  id_ = event->id;

[xhwang, 2017/06/30 16:24:57]

How about adding an access to get the ID from |media_log| directly?

[sandersd (OOO until July 31), 2017/06/30 17:44:30]

I did this by exposing a getter, since MediaLog can't friend
MojoMediaLogService. PTAL.

+}
+
+MojoMediaLogService::~MojoMediaLogService() {
+  DVLOG(1) << __func__;
+}
+
+void MojoMediaLogService::AddEvent(const media::MediaLogEvent& event) {
+  DVLOG(1) << __func__;
+  std::unique_ptr<media::MediaLogEvent> modified_event =
+      base::MakeUnique<media::MediaLogEvent>(event);
+  modified_event->id = id_;

[xhwang, 2017/06/30 16:24:57]

This worth some comment (e.g. the ID is per process...)

[sandersd (OOO until July 31), 2017/06/30 17:44:30]

Done.

+  media_log_->AddEvent(std::move(modified_event));
+}
+
+}  // namespace media