MediaStream API: Update RTCDataChannel to match the specification

Source/core/platform/mediastream/RTCDataChannelHandler.h

Index: Source/core/platform/mediastream/RTCDataChannelHandler.h
diff --git a/Source/core/platform/mediastream/RTCDataChannelHandler.h b/Source/core/platform/mediastream/RTCDataChannelHandler.h
index 18a4055e638bd5b72b4a97348cb24558a5549cfb..70a3076f860c3bfd66635182568bf555922276c9 100644
--- a/Source/core/platform/mediastream/RTCDataChannelHandler.h
+++ b/Source/core/platform/mediastream/RTCDataChannelHandler.h
@@ -43,8 +43,18 @@ public:
 
     void setClient(RTCDataChannelHandlerClient*);
 
-    String label();
-    bool isReliable();
+    String label() const;
+
+    // DEPRECATED
+    bool isReliable() const;
+
+    bool ordered() const;
+    unsigned short maxRetransmitTime() const;
+    unsigned short maxRetransmits() const;
+    String protocol() const;
+    bool negotiated() const;
+    unsigned short id() const;
+
     unsigned long bufferedAmount();
     bool sendStringData(const String&);
     bool sendRawData(const char*, size_t);