Account for HTTP/2 padding in receive windows.

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 7f6452f54ea881f5de65ab076aef034f502dbe67..55c3fa7578e9aee29122ca8610cb2922cc1366bd 100644
--- a/net/spdy/spdy_framer.h
+++ b/net/spdy/spdy_framer.h
@@ -180,6 +180,11 @@ class NET_EXPORT_PRIVATE SpdyFramerVisitorInterface {
                                  size_t len,
                                  bool fin) = 0;
 
+  // Called when padding is received (padding length field or padding octets).
+  // |stream_id| The stream receiving data.
+  // |len| The number of padding octets.
+  virtual void OnStreamPadding(SpdyStreamId stream_id, size_t len) = 0;
+
   // Called when a chunk of header data is available. This is called
   // after OnSynStream, OnSynReply, OnHeaders(), or OnPushPromise.
   // |stream_id| The stream receiving the header data.