media: Add MojoCdmServiceContext.

media/mojo/services/mojo_cdm_service_context.cc

+// Copyright 2014 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/mojo_cdm_service_context.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+
+namespace media {
+
+MojoCdmServiceContext::MojoCdmServiceContext() {
+}
+
+MojoCdmServiceContext::~MojoCdmServiceContext() {
+}
+
+MojoCdmService* MojoCdmServiceContext::Create(
+    const mojo::String& key_system,
+    const mojo::String& security_origin,
+    int32_t cdm_id,
+    mojo::InterfaceRequest<mojo::ContentDecryptionModule> request) {
+  DVLOG(1) << __FUNCTION__ << ": " << key_system;
+
+  // TODO(xhwang): pass |security_origin| down because CdmFactory needs it.
+  MojoCdmService* cdm_service =
+      MojoCdmService::Create(this, key_system, request.Pass());
+  if (cdm_service)
+    services_.add(cdm_id, make_scoped_ptr(cdm_service));
+  return cdm_service;
+}
+
+CdmContext* MojoCdmServiceContext::GetCdmContext(int32_t cdm_id) {

[sandersd (OOO until July 31), 2015/06/04 22:53:08]

The returned pointer can be deleted at any time. What do clients need to do to
be sure they don't try to dereference garbage?

[xhwang, 2015/06/05 18:14:52]

Yes, that's in the plan. Added a TODO to make it clear.

+  MojoCdmService* service = services_.get(cdm_id);
+  if (!service) {
+    LOG(ERROR) << "CDM context not found: " << cdm_id;
+    return nullptr;
+  }
+
+  return service->GetCdmContext();
+}
+
+void MojoCdmServiceContext::ServiceHadConnectionError(MojoCdmService* service) {
+  for (auto it = services_.begin(); it != services_.end(); ++it) {
+    if (it->second == service) {
+      services_.erase(it);  // This destroys the |service|.
+      return;
+    }
+  }
+
+  NOTREACHED() << "Service " << service << " not found.";
+}
+
+}  // namespace media