[webnfc] Implement nfc.watch in blink nfc module.

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

Index: third_party/WebKit/Source/modules/nfc/NFC.h
diff --git a/third_party/WebKit/Source/modules/nfc/NFC.h b/third_party/WebKit/Source/modules/nfc/NFC.h
index 3a4165289dd4c8ade8a68007c0ea48ebf75b0c21..d9f98f23fa733f942defd631ab1693239bdf0d33 100644
--- a/third_party/WebKit/Source/modules/nfc/NFC.h
+++ b/third_party/WebKit/Source/modules/nfc/NFC.h
@@ -11,7 +11,9 @@
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/page/PageVisibilityObserver.h"
 #include "device/nfc/nfc.mojom-blink.h"
+#include "modules/nfc/MessageCallback.h"
 #include "mojo/public/cpp/bindings/binding.h"
+#include "wtf/HashMap.h"
 
 namespace blink {
 
@@ -63,8 +65,13 @@ public:
     DECLARE_VIRTUAL_TRACE();
 
 private:
+    // Returns promise with DOMException if feature is not supported
+    // or when context is not secure. Otherwise, returns empty promise.
+    ScriptPromise RejectIfNotSupported(ScriptState*);

[dcheng, 2016/09/08 04:42:38]

Nit: blink naming convention is still camelCaseWithFirstLetterLowercase. Let's
be consistent with that for the things that aren't implementing mojo methods.

[shalamov, 2016/09/22 13:53:22]

Done.

+
     void OnRequestCompleted(ScriptPromiseResolver*, device::nfc::blink::NFCErrorPtr);
     void OnConnectionError();
+    void OnWatchRegistered(MessageCallback*, ScriptPromiseResolver*, uint32_t id, device::nfc::blink::NFCErrorPtr);
 
     // device::nfc::blink::NFCClient implementation.
     void OnWatch(mojo::WTFArray<uint32_t> ids, device::nfc::blink::NFCMessagePtr) override;
@@ -74,6 +81,8 @@ private:
     device::nfc::blink::NFCPtr m_nfc;
     mojo::Binding<device::nfc::blink::NFCClient> m_client;
     HeapHashSet<Member<ScriptPromiseResolver>> m_requests;
+    using WatchCallbacksMap = HeapHashMap<uint32_t, Member<MessageCallback>>;
+    WatchCallbacksMap m_callbacks;
 };
 
 } // namespace blink