Migrate MIDIAccessInitializer to use GC mojo wrappers.

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

Bug: 1049056
Change-Id: Iaef4f9e9baf735635e2b763bb246749fd0cc55e6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134005
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Minoru Chikamune <chikamune@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756243}

third_party/blink/renderer/modules/webmidi/midi_access_initializer.cc

@@ -30,16 +30,16 @@ using mojom::blink::PermissionStatus;
 
 MIDIAccessInitializer::MIDIAccessInitializer(ScriptState* script_state,
                                              const MIDIOptions* options)
-    : ScriptPromiseResolver(script_state), options_(options) {}
+    : ScriptPromiseResolver(script_state),
+      options_(options),
+      permission_service_(GetExecutionContext()) {}
 
 void MIDIAccessInitializer::Dispose() {
   dispatcher_.reset();
-  permission_service_.reset();
 }
 
 void MIDIAccessInitializer::ContextDestroyed() {
   dispatcher_.reset();
-  permission_service_.reset();
 
   ScriptPromiseResolver::ContextDestroyed();
 }
@@ -126,6 +126,7 @@ void MIDIAccessInitializer::DidStartSession(Result result) {
 
 void MIDIAccessInitializer::Trace(Visitor* visitor) {
   visitor->Trace(options_);
+  visitor->Trace(permission_service_);
   ScriptPromiseResolver::Trace(visitor);
 }
 

third_party/blink/renderer/modules/webmidi/midi_access_initializer.h

@@ -7,7 +7,6 @@
 
 #include <memory>
 #include "media/midi/midi_service.mojom-blink-forward.h"
-#include "mojo/public/cpp/bindings/remote.h"
 #include "third_party/blink/public/mojom/permissions/permission.mojom-blink.h"
 #include "third_party/blink/public/mojom/permissions/permission_status.mojom-blink-forward.h"
 #include "third_party/blink/renderer/bindings/core/v8/script_promise.h"
@@ -16,6 +15,7 @@
 #include "third_party/blink/renderer/modules/modules_export.h"
 #include "third_party/blink/renderer/modules/webmidi/midi_dispatcher.h"
 #include "third_party/blink/renderer/modules/webmidi/midi_port.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_remote.h"
 #include "third_party/blink/renderer/platform/wtf/vector.h"
 
 namespace blink {
@@ -101,7 +101,7 @@ class MODULES_EXPORT MIDIAccessInitializer : public ScriptPromiseResolver,
   Vector<PortDescriptor> port_descriptors_;
   Member<const MIDIOptions> options_;
 
-  mojo::Remote<mojom::blink::PermissionService> permission_service_;
+  HeapMojoRemote<mojom::blink::PermissionService> permission_service_;
 };
 
 }  // namespace blink