[webnfc] Avoid increasing ref-count for |resolver_| in Reader.

The |resolver_| is in the reader, so no need to pass it to a
closure carring the reader already. Also to align with other
places, OnScanRequestCompleted() has been made to be a member
method, so that |resolver_| can be cleared when settled.

Bug: 520391
Change-Id: Ie5718243aa0f60498e042550b33ffcea5700ad84
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2145262
Commit-Queue: Donna Wu <donna.wu@intel.com>
Reviewed-by: Rijubrata Bhaumik <rijubrata.bhaumik@intel.com>
Cr-Commit-Position: refs/heads/master@{#758776}

third_party/blink/renderer/modules/nfc/ndef_reader.cc

@@ -37,16 +37,6 @@ namespace {
 constexpr char kNotSupportedOrPermissionDenied[] =
     "WebNFC feature is unavailable or permission denied.";
 
-void OnScanRequestCompleted(ScriptPromiseResolver* resolver,
-                            device::mojom::blink::NDEFErrorPtr error) {
-  if (error) {
-    resolver->Reject(
-        NDEFErrorTypeToDOMException(error->error_type, error->error_message));
-    return;
-  }
-  resolver->Resolve();
-}
-
 }  // namespace
 
 // static
@@ -118,16 +108,15 @@ ScriptPromise NDEFReader::scan(ScriptState* script_state,
   // 8. If reader.[[Signal]] is not null, then add the following abort steps to
   // reader.[[Signal]]:
   if (options->hasSignal()) {
-    options->signal()->AddAlgorithm(WTF::Bind(&NDEFReader::Abort,
-                                              WrapPersistent(this),
-                                              WrapPersistent(resolver_.Get())));
+    options->signal()->AddAlgorithm(
+        WTF::Bind(&NDEFReader::Abort, WrapPersistent(this)));
   }
 
   GetPermissionService()->RequestPermission(
       CreatePermissionDescriptor(PermissionName::NFC),
       LocalFrame::HasTransientUserActivation(document->GetFrame()),
       WTF::Bind(&NDEFReader::OnRequestPermission, WrapPersistent(this),
-                WrapPersistent(resolver_.Get()), WrapPersistent(options)));
+                WrapPersistent(options)));
   return resolver_->Promise();
 }
 
@@ -140,17 +129,21 @@ PermissionService* NDEFReader::GetPermissionService() {
   return permission_service_.get();
 }
 
-void NDEFReader::OnRequestPermission(ScriptPromiseResolver* resolver,
-                                     const NDEFScanOptions* options,
+void NDEFReader::OnRequestPermission(const NDEFScanOptions* options,
                                      PermissionStatus status) {
+  if (!resolver_)
+    return;
+
   if (status != PermissionStatus::GRANTED) {
-    resolver->Reject(MakeGarbageCollected<DOMException>(
+    resolver_->Reject(MakeGarbageCollected<DOMException>(
         DOMExceptionCode::kNotAllowedError, "NFC permission request denied."));
+    resolver_.Clear();
     return;
   }
   if (options->hasSignal() && options->signal()->aborted()) {
-    resolver->Reject(MakeGarbageCollected<DOMException>(
+    resolver_->Reject(MakeGarbageCollected<DOMException>(
         DOMExceptionCode::kAbortError, "The NFC operation was cancelled."));
+    resolver_.Clear();
     return;
   }
 
@@ -160,7 +153,22 @@ void NDEFReader::OnRequestPermission(ScriptPromiseResolver* resolver,
 
   GetNfcProxy()->StartReading(
       this, options,
-      WTF::Bind(&OnScanRequestCompleted, WrapPersistent(resolver)));
+      WTF::Bind(&NDEFReader::OnScanRequestCompleted, WrapPersistent(this)));
+}
+
+void NDEFReader::OnScanRequestCompleted(
+    device::mojom::blink::NDEFErrorPtr error) {
+  if (!resolver_)
+    return;
+
+  if (error) {
+    resolver_->Reject(
+        NDEFErrorTypeToDOMException(error->error_type, error->error_message));
+  } else {
+    resolver_->Resolve();
+  }
+
+  resolver_.Clear();
 }
 
 void NDEFReader::Trace(Visitor* visitor) {
@@ -190,6 +198,7 @@ void NDEFReader::OnMojoConnectionError() {
     resolver_->Reject(NDEFErrorTypeToDOMException(
         device::mojom::blink::NDEFErrorType::NOT_SUPPORTED,
         kNotSupportedOrPermissionDenied));
+    resolver_.Clear();
   }
 
   // Dispatches an error event.
@@ -202,14 +211,18 @@ void NDEFReader::ContextDestroyed() {
     resolver_->Reject(MakeGarbageCollected<DOMException>(
         DOMExceptionCode::kAbortError,
         "The execution context is going to be gone."));
+    resolver_.Clear();
   }
   GetNfcProxy()->StopReading(this);
 }
 
-void NDEFReader::Abort(ScriptPromiseResolver* resolver) {
-  // If |resolver| has already settled this rejection is silently ignored.
-  resolver->Reject(MakeGarbageCollected<DOMException>(
-      DOMExceptionCode::kAbortError, "The NFC operation was cancelled."));
+void NDEFReader::Abort() {
+  if (resolver_) {
+    resolver_->Reject(MakeGarbageCollected<DOMException>(
+        DOMExceptionCode::kAbortError, "The NFC operation was cancelled."));
+    resolver_.Clear();
+  }
+
   GetNfcProxy()->StopReading(this);
 }
 

third_party/blink/renderer/modules/nfc/ndef_reader.h

@@ -59,13 +59,14 @@ class MODULES_EXPORT NDEFReader : public EventTargetWithInlineData,
   // ExecutionContextLifecycleObserver overrides.
   void ContextDestroyed() override;
 
-  void Abort(ScriptPromiseResolver*);
+  void Abort();
 
   NFCProxy* GetNfcProxy() const;
 
+  void OnScanRequestCompleted(device::mojom::blink::NDEFErrorPtr error);
+
   // Permission handling
-  void OnRequestPermission(ScriptPromiseResolver* resolver,
-                           const NDEFScanOptions* options,
+  void OnRequestPermission(const NDEFScanOptions* options,
                            mojom::blink::PermissionStatus status);
   mojom::blink::PermissionService* GetPermissionService();
   mojo::Remote<mojom::blink::PermissionService> permission_service_;