Add settings IDs to SpdyConstants.

net/spdy/spdy_framer.h

Index: net/spdy/spdy_framer.h
diff --git a/net/spdy/spdy_framer.h b/net/spdy/spdy_framer.h
index 01de6600b2dc697f7d5576a3d5b4fa16290c4074..3188825ad0e224f8feca0da29c34e4fc240cdfc7 100644
--- a/net/spdy/spdy_framer.h
+++ b/net/spdy/spdy_framer.h
@@ -85,7 +85,7 @@ struct NET_EXPORT_PRIVATE SpdySettingsScratch {
 
   void Reset() {
     setting_buf_len = 0;
-    last_setting_id = 0;
+    last_setting_id = -1;
   }
 
   // Buffer contains up to one complete key/value pair.
@@ -96,8 +96,8 @@ struct NET_EXPORT_PRIVATE SpdySettingsScratch {
 
   // The ID of the last setting that was processed in the current SETTINGS
   // frame. Used for detecting out-of-order or duplicate keys within a settings
-  // frame. Set to 0 before first key/value pair is processed.
-  uint32 last_setting_id;
+  // frame. Set to -1 before first key/value pair is processed.
+  int last_setting_id;
 };
 
 // SpdyFramerVisitorInterface is a set of callbacks for the SpdyFramer.