[webnfc] Allow access to WebNFC API only from main frame

third_party/WebKit/Source/modules/nfc/NFC.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/nfc/NFC.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/V8ArrayBuffer.h"
 #include "bindings/core/v8/V8StringResource.h"
 #include "core/dom/DOMArrayBuffer.h"
@@ skipping 762 matching lines @@
       DCHECK(scriptState);
       ScriptState::Scope scope(scriptState);
       NFCMessage nfcMessage = toNFCMessage(scriptState, message);
       callback->handleMessage(nfcMessage);
     }
   }
 }
 
 ScriptPromise NFC::rejectIfNotSupported(ScriptState* scriptState) {
   String errorMessage;
-  if (!scriptState->getExecutionContext()->isSecureContext(errorMessage)) {
+  ExecutionContext* context = scriptState->getExecutionContext();
+  if (!context->isSecureContext(errorMessage)) {
     return ScriptPromise::rejectWithDOMException(
         scriptState, DOMException::create(SecurityError, errorMessage));
   }
 
+  // https://w3c.github.io/web-nfc/#security-policies
+  // WebNFC API must be only accessible from top level browsing context.
+  if (!toDocument(context)->domWindow()->frame() ||
+      !toDocument(context)->frame()->isMainFrame()) {
+    return ScriptPromise::rejectWithDOMException(
+        scriptState,
+        DOMException::create(SecurityError,
+                             "Must be in a top-level browsing context."));
+  }
+
   if (!m_nfc) {
     return ScriptPromise::rejectWithDOMException(
         scriptState, DOMException::create(NotSupportedError));
   }
 
   return ScriptPromise();
 }
 
 void NFC::OnWatchRegistered(MessageCallback* callback,
                             ScriptPromiseResolver* resolver,
@@ skipping 20 matching lines @@
 }
 
 DEFINE_TRACE(NFC) {
   PageVisibilityObserver::trace(visitor);
   ContextLifecycleObserver::trace(visitor);
   visitor->trace(m_requests);
   visitor->trace(m_callbacks);
 }
 
 }  // namespace blink