Add Promises for EME (Chromium side)

Now that the EME-WD spec has changed to specify promises, implement
them on the Chromium side. They currently get converted back to
events before passing them to blink:: until the blink interface gets
changed.

Additional changes in this CL:
1. Pass a reference to the promise though PPAPI.
2. Roll DEPS for CDM.h to include CDM_5.
3. Update cdm_adapter to use CDM_5 (in addition to existing CDM_4).
4. Change External Clear Key to use CDM_5.
5. Since CDM_5 references sessions by the actual session id (a string,
   web_session_id), switch to using it rather than the previously used
   session_id (which is an integer, and used as a reference).

BUG=358271
TEST=all existing encrypted media layout and browser tests pass

Review URL: https://codereview.chromium.org/265993002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275656 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 74 insertions, 0 deletions

diff --git a/media/base/cdm_promise.cc b/media/base/cdm_promise.cc
new file mode 100644
index 0000000..ec5e913
--- /dev/null
+++ b/media/base/cdm_promise.cc
@@ -0,0 +1,74 @@
+// 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/base/cdm_promise.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+
+namespace media {
+
+CdmPromise::CdmPromise() : is_pending_(true) {
+}
+
+CdmPromise::CdmPromise(PromiseRejectedCB reject_cb)
+    : reject_cb_(reject_cb), is_pending_(true) {
+  DCHECK(!reject_cb_.is_null());
+}
+
+CdmPromise::~CdmPromise() {
+  DCHECK(!is_pending_);
+}
+
+void CdmPromise::reject(MediaKeys::Exception exception_code,
+                        uint32 system_code,
+                        const std::string& error_message) {
+  DCHECK(is_pending_);
+  is_pending_ = false;
+  reject_cb_.Run(exception_code, system_code, error_message);
+}
+
+template <typename T>
+CdmPromiseTemplate<T>::CdmPromiseTemplate(
+    base::Callback<void(const T&)> resolve_cb,
+    PromiseRejectedCB reject_cb)
+    : CdmPromise(reject_cb), resolve_cb_(resolve_cb) {
+  DCHECK(!resolve_cb_.is_null());
+}
+
+template <typename T>
+CdmPromiseTemplate<T>::~CdmPromiseTemplate() {
+  DCHECK(!is_pending_);
+}
+
+template <typename T>
+void CdmPromiseTemplate<T>::resolve(const T& result) {
+  DCHECK(is_pending_);
+  is_pending_ = false;
+  resolve_cb_.Run(result);
+}
+
+CdmPromiseTemplate<void>::CdmPromiseTemplate(base::Callback<void()> resolve_cb,
+                                             PromiseRejectedCB reject_cb)
+    : CdmPromise(reject_cb), resolve_cb_(resolve_cb) {
+  DCHECK(!resolve_cb_.is_null());
+}
+
+CdmPromiseTemplate<void>::CdmPromiseTemplate() {
+}
+
+CdmPromiseTemplate<void>::~CdmPromiseTemplate() {
+  DCHECK(!is_pending_);
+}
+
+void CdmPromiseTemplate<void>::resolve() {
+  DCHECK(is_pending_);
+  is_pending_ = false;
+  resolve_cb_.Run();
+}
+
+// Explicit template instantiation for the Promises needed.
+template class MEDIA_EXPORT CdmPromiseTemplate<std::string>;
+
+}  // namespace media