Migrate Serial to use GC mojo wrappers.

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

Bug: 1049056
Change-Id: Ica922d40136c54683d995e134cdc3df0ea6d8dd1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2135667Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Minoru Chikamune <chikamune@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756242}

third_party/blink/renderer/modules/serial/serial.cc

@@ -42,7 +42,9 @@ String TokenToString(const base::UnguessableToken& token) {
 }  // namespace
 
 Serial::Serial(ExecutionContext& execution_context)
-    : ExecutionContextLifecycleObserver(&execution_context) {}
+    : ExecutionContextLifecycleObserver(&execution_context),
+      service_(&execution_context),
+      receiver_(this, &execution_context) {}
 
 ExecutionContext* Serial::GetExecutionContext() const {
   return ExecutionContextLifecycleObserver::GetExecutionContext();
@@ -155,10 +157,6 @@ ScriptPromise Serial::requestPort(ScriptState* script_state,
   return resolver->Promise();
 }
 
-void Serial::Dispose() {
-  receiver_.reset();
-}
-
 void Serial::GetPort(
     const base::UnguessableToken& token,
     mojo::PendingReceiver<device::mojom::blink::SerialPort> receiver) {
@@ -167,6 +165,8 @@ void Serial::GetPort(
 }
 
 void Serial::Trace(Visitor* visitor) {
+  visitor->Trace(service_);
+  visitor->Trace(receiver_);
   visitor->Trace(get_ports_promises_);
   visitor->Trace(request_port_promises_);
   visitor->Trace(port_cache_);
@@ -196,7 +196,7 @@ void Serial::AddedEventListener(const AtomicString& event_type,
 void Serial::EnsureServiceConnection() {
   DCHECK(GetExecutionContext());
 
-  if (service_)
+  if (service_.is_bound())
     return;
 
   auto task_runner =
@@ -206,7 +206,7 @@ void Serial::EnsureServiceConnection() {
   service_.set_disconnect_handler(
       WTF::Bind(&Serial::OnServiceConnectionError, WrapWeakPersistent(this)));
 
-  service_->SetClient(receiver_.BindNewPipeAndPassRemote());
+  service_->SetClient(receiver_.BindNewPipeAndPassRemote(task_runner));
 }
 
 void Serial::OnServiceConnectionError() {

third_party/blink/renderer/modules/serial/serial.h

@@ -5,8 +5,6 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_SERIAL_SERIAL_H_
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_SERIAL_SERIAL_H_
 
-#include "mojo/public/cpp/bindings/receiver.h"
-#include "mojo/public/cpp/bindings/remote.h"
 #include "third_party/blink/public/mojom/serial/serial.mojom-blink.h"
 #include "third_party/blink/renderer/bindings/core/v8/script_promise.h"
 #include "third_party/blink/renderer/core/dom/events/event_target.h"
@@ -14,6 +12,9 @@
 #include "third_party/blink/renderer/platform/bindings/script_wrappable.h"
 #include "third_party/blink/renderer/platform/heap/garbage_collected.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/wtf/functional.h"
 
 namespace blink {
@@ -29,7 +30,6 @@ class Serial final : public EventTargetWithInlineData,
                      public mojom::blink::SerialServiceClient {
   DEFINE_WRAPPERTYPEINFO();
   USING_GARBAGE_COLLECTED_MIXIN(Serial);
-  USING_PRE_FINALIZER(Serial, Dispose);
 
  public:
   explicit Serial(ExecutionContext&);
@@ -53,7 +53,6 @@ class Serial final : public EventTargetWithInlineData,
                             const SerialPortRequestOptions*,
                             ExceptionState&);
 
-  void Dispose();
   void GetPort(
       const base::UnguessableToken& token,
       mojo::PendingReceiver<device::mojom::blink::SerialPort> receiver);
@@ -72,8 +71,12 @@ class Serial final : public EventTargetWithInlineData,
                   Vector<mojom::blink::SerialPortInfoPtr>);
   void OnRequestPort(ScriptPromiseResolver*, mojom::blink::SerialPortInfoPtr);
 
-  mojo::Remote<mojom::blink::SerialService> service_;
-  mojo::Receiver<mojom::blink::SerialServiceClient> receiver_{this};
+  HeapMojoRemote<mojom::blink::SerialService,
+                 HeapMojoWrapperMode::kWithoutContextObserver>
+      service_;
+  HeapMojoReceiver<mojom::blink::SerialServiceClient,
+                   HeapMojoWrapperMode::kWithoutContextObserver>
+      receiver_;
   HeapHashSet<Member<ScriptPromiseResolver>> get_ports_promises_;
   HeapHashSet<Member<ScriptPromiseResolver>> request_port_promises_;
   HeapHashMap<String, WeakMember<SerialPort>> port_cache_;