media: Add ServiceFactory mojo interface and implementation.

media/mojo/services/service_factory_impl.cc

+// Copyright 2015 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/services/service_factory_impl.h"
+
+#include "base/logging.h"
+#include "media/base/cdm_factory.h"
+#include "media/base/media_log.h"
+#include "media/base/renderer_factory.h"
+#include "media/mojo/services/mojo_cdm_service.h"
+#include "media/mojo/services/mojo_media_client.h"
+#include "media/mojo/services/mojo_renderer_service.h"
+
+namespace media {
+
+ServiceFactoryImpl::ServiceFactoryImpl(
+    mojo::InterfaceRequest<interfaces::ServiceFactory> request,
+    mojo::ServiceProvider* service_provider,
+    scoped_refptr<MediaLog> media_log)
+    : binding_(this, request.Pass()),
+      service_provider_(service_provider),
+      media_log_(media_log) {
+  DVLOG(1) << __FUNCTION__;
+}
+
+ServiceFactoryImpl::~ServiceFactoryImpl() {
+  DVLOG(1) << __FUNCTION__;
+}
+
+// interfaces::ServiceFactory implementation.
+void ServiceFactoryImpl::CreateRenderer(
+    mojo::InterfaceRequest<interfaces::MediaRenderer> request) {
+  // The created object is owned by the pipe.
+  new MojoRendererService(cdm_service_context_.GetWeakPtr(),
+                          GetRendererFactory(), media_log_, request.Pass());
+}
+
+void ServiceFactoryImpl::CreateCdm(
+    mojo::InterfaceRequest<interfaces::ContentDecryptionModule> request) {
+  // The created object is owned by the pipe.
+  new MojoCdmService(cdm_service_context_.GetWeakPtr(), service_provider_,

[xhwang, 2015/07/18 00:03:55]

Previously |cdm_service_context_| is owned by the app, which is assumed to
always outlive the services, so we pass the raw pointer to cdm_service_context_
here.

Now that |cdm_service_context_| is owned by ServiceFactoryImpl, which itself is
a service. Since service can go at any time (using StrongBind), I am using weak
pointers to prevent access violation.

Maybe I should not use StrongBind for ServiceFactoryImpl so that
ServiceFactoryImpl will always outlive the services it created. But I'd like to
defer this to the next CL...

+                     GetCdmFactory(), request.Pass());
+}
+
+RendererFactory* ServiceFactoryImpl::GetRendererFactory() {
+  if (!renderer_factory_)
+    renderer_factory_ =
+        MojoMediaClient::Get()->CreateRendererFactory(media_log_);
+  return renderer_factory_.get();
+}
+
+CdmFactory* ServiceFactoryImpl::GetCdmFactory() {
+  if (!cdm_factory_)
+    cdm_factory_ = MojoMediaClient::Get()->CreateCdmFactory();
+  return cdm_factory_.get();
+}
+
+}  // namespace media