media: Avoid access violation in MojoCdm after connection error

media/mojo/clients/mojo_cdm.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/clients/mojo_cdm.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 94 matching lines @@
 
   // If connection error has happened, fail immediately.
   if (remote_cdm_.encountered_error()) {
     LOG(ERROR) << "Remote CDM encountered error.";
     promise->reject(CdmPromise::NOT_SUPPORTED_ERROR, 0,
                     "Mojo CDM creation failed.");
     return;
   }
 
   // Otherwise, set an error handler to catch the connection error.
-  remote_cdm_.set_connection_error_handler(
+  remote_cdm_.set_connection_error_with_reason_handler(
       base::Bind(&MojoCdm::OnConnectionError, base::Unretained(this)));
 
   pending_init_promise_ = std::move(promise);
 
   remote_cdm_->Initialize(
       key_system, security_origin.spec(), mojom::CdmConfig::From(cdm_config),
       base::Bind(&MojoCdm::OnCdmInitialized, base::Unretained(this)));
 }
 
-void MojoCdm::OnConnectionError() {
-  LOG(ERROR) << "Remote CDM connection error.";
+// TODO(xhwang): Properly handle CDM calls after connection error.
+// See http://crbug.com/671362
+void MojoCdm::OnConnectionError(uint32_t custom_reason,
+                                const std::string& description) {
+  LOG(ERROR) << "Remote CDM connection error: custom_reason=" << custom_reason
+             << ", description=\"" << description << "\"";
   DCHECK(thread_checker_.CalledOnValidThread());
 
   // Handle initial connection error.
   if (pending_init_promise_) {
+    DCHECK(!cdm_session_tracker_.HasRemainingSessions());
     pending_init_promise_->reject(CdmPromise::NOT_SUPPORTED_ERROR, 0,
                                   "Mojo CDM creation failed.");
+    // Dropping the promise could cause |this| to be destructed.
     pending_init_promise_.reset();
+    return;
   }
 
   cdm_session_tracker_.CloseRemainingSessions(session_closed_cb_);
 }
 
 void MojoCdm::SetServerCertificate(const std::vector<uint8_t>& certificate,
                                    std::unique_ptr<SimpleCdmPromise> promise) {
   DVLOG(2) << __func__;
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ skipping 193 matching lines @@
     mojom::CdmPromiseResultPtr result,
     const std::string& session_id) {
   if (result->success) {
     cdm_session_tracker_.AddSession(session_id);
     promise->resolve(session_id);
   } else
     RejectPromise(std::move(promise), std::move(result));
 }
 
 }  // namespace media