Instead of enqueueing SPDY frames, enqueue SPDY streams that are ready to produce data.

net/spdy/spdy_io_buffer.h

Index: net/spdy/spdy_io_buffer.h
diff --git a/net/spdy/spdy_io_buffer.h b/net/spdy/spdy_io_buffer.h
index e4033c2309dd5d9056fef30b689949feb3c4a23b..9bbee1612a6a9bb95e053ad4f4f4d8ac68fb0aff 100644
--- a/net/spdy/spdy_io_buffer.h
+++ b/net/spdy/spdy_io_buffer.h
@@ -8,10 +8,12 @@
 #include "base/memory/ref_counted.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_export.h"
-#include "net/spdy/spdy_stream.h"
+#include "net/base/request_priority.h"
 
 namespace net {
 
+class SpdyStream;
+
 // A class for managing SPDY IO buffers.  These buffers need to be prioritized
 // so that the SpdySession sends them in the right order.  Further, they need
 // to track the SpdyStream which they are associated with so that incremental
@@ -25,8 +27,14 @@ class NET_EXPORT_PRIVATE SpdyIOBuffer {
   // |stream| is a pointer to the stream which is managing this buffer.
   SpdyIOBuffer(IOBuffer* buffer, int size, RequestPriority priority,
                SpdyStream* stream);
+  // Declare this instead of using the default so that we avoid needing to
+  // include spdy_stream.h.
+  SpdyIOBuffer(const SpdyIOBuffer& rhs);
   SpdyIOBuffer();
   ~SpdyIOBuffer();
+  // Declare this instead of using the default so that we avoid needing to
+  // include spdy_stream.h.
+  SpdyIOBuffer& operator=(const SpdyIOBuffer& rhs);
 
   // Accessors.
   DrainableIOBuffer* buffer() const { return buffer_; }