[webnfc] Implement push() method in blink nfc module.

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

 // 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.
 
 #ifndef NFC_h
 #define NFC_h
 
+#include "bindings/core/v8/CallbackPromiseAdapter.h"

[Reilly Grant (use Gerrit), 2016/04/27 23:32:53]

Unused header.

[shalamov, 2016/04/28 14:16:14]

Done.

 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/modules/v8/UnionTypesModules.h"
-#include "core/frame/LocalFrameLifecycleObserver.h"
 #include "core/page/PageLifecycleObserver.h"
+#include "device/nfc/nfc.mojom-wtf.h"
+#include "mojo/public/cpp/bindings/binding.h"
 
 namespace blink {
 
 class MessageCallback;
+class NFCError;
 class NFCPushOptions;
 using NFCPushMessage = StringOrArrayBufferOrNFCMessage;
 class NFCWatchOptions;
+class ServiceRegistry;
 
 class NFC final
-    : public GarbageCollected<NFC>
+    : public GarbageCollectedFinalized<NFC>
     , public ScriptWrappable
-    , public LocalFrameLifecycleObserver
-    , public PageLifecycleObserver {
+    , public PageLifecycleObserver
+    , WTF_NON_EXPORTED_BASE(public device::wtf::NFCClient)
+{
     DEFINE_WRAPPERTYPEINFO();
     USING_GARBAGE_COLLECTED_MIXIN(NFC);
 
 public:
     static NFC* create(LocalFrame*);
 
+    virtual ~NFC();
+
     // Pushes NFCPushMessage asynchronously to NFC tag / peer.
     ScriptPromise push(ScriptState*, const NFCPushMessage&, const NFCPushOptions&);
 
     // Cancels ongoing push operation.
     ScriptPromise cancelPush(ScriptState*, const String&);
 
     // Starts watching for NFC messages that match NFCWatchOptions criteria.
     ScriptPromise watch(ScriptState*, MessageCallback*, const NFCWatchOptions&);
 
     // Cancels watch operation with id.
     ScriptPromise cancelWatch(ScriptState*, long id);
 
     // Cancels all watch operations.
     ScriptPromise cancelWatch(ScriptState*);
 
-    // Implementation of LocalFrameLifecycleObserver.
-    void willDetachFrameHost() override;
-
     // Implementation of PageLifecycleObserver.
     void pageVisibilityChanged() override;
 
     // Interface required by garbage collection.
     DECLARE_VIRTUAL_TRACE();
 
 private:
+    bool Initialize(ServiceRegistry*);
+    void OnRequestCompleted(ScriptPromiseResolver*, device::wtf::NFCErrorPtr);
+    // device::wtf::NFCClient implementation
+    void OnWatch(uint32_t id, device::wtf::NFCMessagePtr) override;
+
+private:
     explicit NFC(LocalFrame*);
+    device::wtf::NFCPtr m_nfc;
+    mojo::Binding<device::wtf::NFCClient> m_client;

[Reilly Grant (use Gerrit), 2016/04/27 23:32:53]

When building the USB Mojo interface rockot@ recommended against creating a
client interface like this because it introduces a vulnerability: the render
process can cause the message queue in the browser process to back up by
refusing to read messages. A "get next event" interface like I have in
device::usb::DeviceManager::GetDeviceChanges was recommended instead.

[shalamov, 2016/04/28 14:16:14]

Done.

[Reilly Grant (use Gerrit), 2016/04/28 18:05:02]

After checking again with rockot@ I was told that updates to the Mojo EDK make
this style of interface no longer an issue. A client interface for callbacks
such as this is now recommended. Sorry for the confusion.

+    HeapHashSet<Member<ScriptPromiseResolver>> m_requests;
 };
 
 } // namespace blink
 
 #endif // NFC_h