[SPDY] Refactor SpdySession's write queue

net/spdy/spdy_io_buffer.cc

Index: net/spdy/spdy_io_buffer.cc
diff --git a/net/spdy/spdy_io_buffer.cc b/net/spdy/spdy_io_buffer.cc
index f0c14b12f6aad8852d194cf8dec673937e60eb3b..441b033a57ada88001541bfc22da0af9fac1cd36 100644
--- a/net/spdy/spdy_io_buffer.cc
+++ b/net/spdy/spdy_io_buffer.cc
@@ -7,23 +7,13 @@
 
 namespace net {
 
-// static
-uint64 SpdyIOBuffer::order_ = 0;
+SpdyIOBuffer::SpdyIOBuffer() {}
 
-SpdyIOBuffer::SpdyIOBuffer(
-    IOBuffer* buffer, int size, RequestPriority priority, SpdyStream* stream)
-  : buffer_(new DrainableIOBuffer(buffer, size)),
-    priority_(priority),
-    position_(++order_),
-    stream_(stream) {}
-
-SpdyIOBuffer::SpdyIOBuffer() : priority_(HIGHEST), position_(0), stream_(NULL) {
-}
+SpdyIOBuffer::SpdyIOBuffer(IOBuffer* buffer, int size, SpdyStream* stream)
+  : buffer_(new DrainableIOBuffer(buffer, size)), stream_(stream) {}
 
 SpdyIOBuffer::SpdyIOBuffer(const SpdyIOBuffer& rhs) {
   buffer_ = rhs.buffer_;
-  priority_ = rhs.priority_;
-  position_ = rhs.position_;
   stream_ = rhs.stream_;
 }
 
@@ -31,13 +21,16 @@ SpdyIOBuffer::~SpdyIOBuffer() {}
 
 SpdyIOBuffer& SpdyIOBuffer::operator=(const SpdyIOBuffer& rhs) {
   buffer_ = rhs.buffer_;
-  priority_ = rhs.priority_;
-  position_ = rhs.position_;
   stream_ = rhs.stream_;
   return *this;
 }
 
-void SpdyIOBuffer::release() {
+void SpdyIOBuffer::Swap(SpdyIOBuffer* other) {
+  buffer_.swap(other->buffer_);
+  stream_.swap(other->stream_);
+}
+
+void SpdyIOBuffer::Release() {
   buffer_ = NULL;
   stream_ = NULL;
 }