Migrate RemotePlayback to use GC mojo wrappers.

No behavior change. This CL reduces potential risks of use-after-free bugs.

Bug: 1049056
Change-Id: Ib5730a2d4ef21520c2032c7a010c00e84812e387
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2169433
Commit-Queue: Minoru Chikamune <chikamune@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#766287}

third_party/blink/renderer/modules/remoteplayback/remote_playback.cc

@@ -96,7 +96,9 @@ RemotePlayback::RemotePlayback(HTMLMediaElement& element)
       state_(mojom::blink::PresentationConnectionState::CLOSED),
       availability_(mojom::ScreenAvailability::UNKNOWN),
       media_element_(&element),
-      is_listening_(false) {}
+      is_listening_(false),
+      presentation_connection_receiver_(this, element.GetExecutionContext()),
+      target_presentation_connection_(element.GetExecutionContext()) {}
 
 const AtomicString& RemotePlayback::InterfaceName() const {
   return event_target_names::kRemotePlayback;
@@ -244,10 +246,6 @@ bool RemotePlayback::HasPendingActivity() const {
          prompt_promise_resolver_;
 }
 
-void RemotePlayback::ContextDestroyed() {
-  CleanupConnections();
-}
-
 void RemotePlayback::PromptInternal() {
   if (!GetExecutionContext())
     return;
@@ -528,9 +526,12 @@ void RemotePlayback::OnConnectionSuccess(
     return;
 
   // Note: Messages on |connection_receiver| are ignored.
-  target_presentation_connection_.Bind(std::move(result->connection_remote));
+  target_presentation_connection_.Bind(
+      std::move(result->connection_remote),
+      GetExecutionContext()->GetTaskRunner(TaskType::kMediaElementEvent));
   presentation_connection_receiver_.Bind(
-      std::move(result->connection_receiver));
+      std::move(result->connection_receiver),
+      GetExecutionContext()->GetTaskRunner(TaskType::kMediaElementEvent));
 }
 
 void RemotePlayback::OnConnectionError(
@@ -608,6 +609,8 @@ void RemotePlayback::Trace(Visitor* visitor) {
   visitor->Trace(availability_callbacks_);
   visitor->Trace(prompt_promise_resolver_);
   visitor->Trace(media_element_);
+  visitor->Trace(presentation_connection_receiver_);
+  visitor->Trace(target_presentation_connection_);
   visitor->Trace(observers_);
   EventTargetWithInlineData::Trace(visitor);
   ExecutionContextLifecycleObserver::Trace(visitor);

third_party/blink/renderer/modules/remoteplayback/remote_playback.h

@@ -6,8 +6,6 @@
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_REMOTEPLAYBACK_REMOTE_PLAYBACK_H_
 
 #include "base/macros.h"
-#include "mojo/public/cpp/bindings/receiver.h"
-#include "mojo/public/cpp/bindings/remote.h"
 #include "third_party/blink/public/mojom/presentation/presentation.mojom-blink.h"
 #include "third_party/blink/public/platform/modules/remoteplayback/web_remote_playback_client.h"
 #include "third_party/blink/public/platform/web_url.h"
@@ -20,6 +18,9 @@
 #include "third_party/blink/renderer/modules/modules_export.h"
 #include "third_party/blink/renderer/modules/presentation/presentation_availability_observer.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_receiver.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_remote.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_wrapper_mode.h"
 #include "third_party/blink/renderer/platform/weborigin/kurl.h"
 #include "third_party/blink/renderer/platform/wtf/text/atomic_string.h"
 #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
@@ -126,7 +127,7 @@ class MODULES_EXPORT RemotePlayback final
   bool HasPendingActivity() const final;
 
   // ExecutionContextLifecycleObserver implementation.
-  void ContextDestroyed() override;
+  void ContextDestroyed() override {}
 
   // Adjusts the internal state of |this| after a playback state change.
   void StateChanged(mojom::blink::PresentationConnectionState);
@@ -171,9 +172,9 @@ class MODULES_EXPORT RemotePlayback final
   String presentation_id_;
   KURL presentation_url_;
 
-  mojo::Receiver<mojom::blink::PresentationConnection>
-      presentation_connection_receiver_{this};
-  mojo::Remote<mojom::blink::PresentationConnection>
+  HeapMojoReceiver<mojom::blink::PresentationConnection, RemotePlayback>
+      presentation_connection_receiver_;
+  HeapMojoRemote<mojom::blink::PresentationConnection>
       target_presentation_connection_;
 
   HeapHashSet<Member<RemotePlaybackObserver>> observers_;