media: Keep |cdm_context_ref_| in mojo media services on failure

When unexpected failure happens, we expect the service to stay in a
valid state.

Bug: 1004730
Test: Manually tested
Change-Id: Ib35035705e4604b9aa8cf5212de07bc1069e73d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1810846
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: John Rummell <jrummell@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697907}

media/mojo/services/mojo_audio_decoder_service.cc

@@ -40,13 +40,16 @@ void MojoAudioDecoderService::Initialize(const AudioDecoderConfig& config,
   // Get CdmContext from cdm_id if the stream is encrypted.
   CdmContext* cdm_context = nullptr;
   if (config.is_encrypted()) {
-    cdm_context_ref_ = mojo_cdm_service_context_->GetCdmContextRef(cdm_id);
-    if (!cdm_context_ref_) {
+    auto cdm_context_ref = mojo_cdm_service_context_->GetCdmContextRef(cdm_id);
+    if (!cdm_context_ref) {
       DVLOG(1) << "CdmContextRef not found for CDM id: " << cdm_id;
       std::move(callback).Run(false, false);
       return;
     }
 
+    // |cdm_context_ref_| must be kept as long as |cdm_context| is used by the
+    // |decoder_|.
+    cdm_context_ref_ = std::move(cdm_context_ref);
     cdm_context = cdm_context_ref_->GetCdmContext();
     DCHECK(cdm_context);
   }

media/mojo/services/mojo_renderer_service.cc

@@ -127,13 +127,16 @@ void MojoRendererService::SetCdm(int32_t cdm_id, SetCdmCallback callback) {
     return;
   }
 
-  cdm_context_ref_ = mojo_cdm_service_context_->GetCdmContextRef(cdm_id);
-  if (!cdm_context_ref_) {
+  auto cdm_context_ref = mojo_cdm_service_context_->GetCdmContextRef(cdm_id);
+  if (!cdm_context_ref) {
     DVLOG(1) << "CdmContextRef not found for CDM ID: " << cdm_id;
     std::move(callback).Run(false);
     return;
   }
 
+  // |cdm_context_ref_| must be kept as long as |cdm_context| is used by the
+  // |renderer_|.
+  cdm_context_ref_ = std::move(cdm_context_ref);
   auto* cdm_context = cdm_context_ref_->GetCdmContext();
   DCHECK(cdm_context);
 

media/mojo/services/mojo_video_decoder_service.cc

@@ -178,13 +178,16 @@ void MojoVideoDecoderService::Initialize(const VideoDecoderConfig& config,
   // Get CdmContext from cdm_id if the stream is encrypted.
   CdmContext* cdm_context = nullptr;
   if (cdm_id != CdmContext::kInvalidCdmId) {
-    cdm_context_ref_ = mojo_cdm_service_context_->GetCdmContextRef(cdm_id);
-    if (!cdm_context_ref_) {
+    auto cdm_context_ref = mojo_cdm_service_context_->GetCdmContextRef(cdm_id);
+    if (!cdm_context_ref) {
       DVLOG(1) << "CdmContextRef not found for CDM id: " << cdm_id;
       OnDecoderInitialized(false);
       return;
     }
 
+    // |cdm_context_ref_| must be kept as long as |cdm_context| is used by the
+    // |decoder_|.
+    cdm_context_ref_ = std::move(cdm_context_ref);
     cdm_context = cdm_context_ref_->GetCdmContext();
     DCHECK(cdm_context);
   }