Keep reference to CDM to avoid it's premature destruction

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 7c67743e982b430e3c7794a1e1d2a3310806ee3c..cdebe7739579127cc1db0a4aadd49269324e37b7 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -32,6 +32,7 @@
 #include "media/base/cdm_context.h"
 #include "media/base/limits.h"
 #include "media/base/media_content_type.h"
+#include "media/base/media_keys.h"
 #include "media/base/media_log.h"
 #include "media/base/media_switches.h"
 #include "media/base/text_renderer.h"
@@ -215,7 +216,6 @@ WebMediaPlayerImpl::WebMediaPlayerImpl(
                                   ? params.compositor_task_runner()
                                   : base::ThreadTaskRunnerHandle::Get()),
       compositor_(new VideoFrameCompositor(compositor_task_runner_)),
-      is_cdm_attached_(false),
 #if defined(OS_ANDROID)  // WMPI_CAST
       cast_impl_(this, client_, params.context_3d_cb()),
 #endif
@@ -244,11 +244,8 @@ WebMediaPlayerImpl::WebMediaPlayerImpl(
   media_log_->AddEvent(
       media_log_->CreateEvent(MediaLogEvent::WEBMEDIAPLAYER_CREATED));
 
-  if (params.initial_cdm()) {
-    SetCdm(base::Bind(&IgnoreCdmAttached),
-           ToWebContentDecryptionModuleImpl(params.initial_cdm())
-               ->GetCdmContext());
-  }
+  if (params.initial_cdm())
+    SetCdm(params.initial_cdm());
 
   // TODO(xhwang): When we use an external Renderer, many methods won't work,
   // e.g. GetCurrentFrameFromCompositor(). See http://crbug.com/434861
@@ -780,7 +777,7 @@ void WebMediaPlayerImpl::paint(blink::WebCanvas* canvas,
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   TRACE_EVENT0("media", "WebMediaPlayerImpl:paint");
 
-  if (is_cdm_attached_)
+  if (cdm_)
     return;
 
   scoped_refptr<VideoFrame> video_frame = GetCurrentFrameFromCompositor();
@@ -895,8 +892,7 @@ void WebMediaPlayerImpl::setContentDecryptionModule(
   if (!was_encrypted && watch_time_reporter_)
     CreateWatchTimeReporter();
 
-  SetCdm(BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnCdmAttached),
-         ToWebContentDecryptionModuleImpl(cdm)->GetCdmContext());
+  SetCdm(cdm);
 }
 
 void WebMediaPlayerImpl::OnEncryptedMediaInitData(
@@ -946,29 +942,54 @@ void WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated(
   }
 }
 
-void WebMediaPlayerImpl::SetCdm(const CdmAttachedCB& cdm_attached_cb,
-                                CdmContext* cdm_context) {
+void WebMediaPlayerImpl::SetCdm(blink::WebContentDecryptionModule* cdm) {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  DCHECK(cdm);
+  scoped_refptr<MediaKeys> cdm_reference =
+      ToWebContentDecryptionModuleImpl(cdm)->GetCdm();
+  if (!cdm_reference) {
+    NOTREACHED();
+    OnCdmAttached(false);
+    return;
+  }
+
+  CdmContext* cdm_context = cdm_reference->GetCdmContext();
   if (!cdm_context) {
-    cdm_attached_cb.Run(false);
+    OnCdmAttached(false);
     return;
   }
 
-  // If CDM initialization succeeded, tell the pipeline about it.
-  pipeline_.SetCdm(cdm_context, cdm_attached_cb);
+  // Keep the reference to the CDM, as it shouldn't be destroyed until
+  // after the pipeline is done with the |cdm_context|.
+  pending_cdm_ = std::move(cdm_reference);
+  pipeline_.SetCdm(cdm_context,
+                   base::Bind(&WebMediaPlayerImpl::OnCdmAttached, AsWeakPtr()));
 }
 
 void WebMediaPlayerImpl::OnCdmAttached(bool success) {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  DCHECK(pending_cdm_);
+
+  // If the CDM is set from the constructor there is no promise
+  // (|set_cdm_result_|) to fulfill.
   if (success) {
-    set_cdm_result_->complete();
-    set_cdm_result_.reset();
-    is_cdm_attached_ = true;
+    // This will release the previously attached CDM (if any).
+    cdm_ = std::move(pending_cdm_);
+    if (set_cdm_result_) {
+      set_cdm_result_->complete();
+      set_cdm_result_.reset();
+    }
+
     return;
   }
 
-  set_cdm_result_->completeWithError(
-      blink::WebContentDecryptionModuleExceptionNotSupportedError, 0,
-      "Unable to set MediaKeys object");
-  set_cdm_result_.reset();
+  pending_cdm_ = nullptr;
+  if (set_cdm_result_) {
+    set_cdm_result_->completeWithError(
+        blink::WebContentDecryptionModuleExceptionNotSupportedError, 0,
+        "Unable to set MediaKeys object");
+    set_cdm_result_.reset();
+  }
 }
 
 void WebMediaPlayerImpl::OnPipelineSeeked(bool time_updated) {