Do not use SpdyFrameBuilder::OverwriteLength().

net/spdy/spdy_frame_builder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/spdy/spdy_frame_builder.h"
 
 #include <limits>
 
 #include "base/logging.h"
 #include "net/spdy/spdy_bug_tracker.h"
@@ skipping 47 matching lines @@
   // Don't check for length limits here because this may be larger than the
   // actual frame length.
   success &= WriteUInt24(capacity_ - offset_ - kFrameHeaderSize);
   success &= WriteUInt8(SerializeFrameType(type));
   success &= WriteUInt8(flags);
   success &= WriteUInt32(stream_id);
   DCHECK_EQ(framer.GetDataFrameMinimumSize(), length_);
   return success;
 }
 
+bool SpdyFrameBuilder::BeginNewFrame(const SpdyFramer& framer,
+                                     SpdyFrameType type,
+                                     uint8_t flags,
+                                     SpdyStreamId stream_id,
+                                     size_t length) {
+  DCHECK(IsValidFrameType(SerializeFrameType(type)));
+  DCHECK_EQ(0u, stream_id & ~kStreamIdMask);
+  bool success = true;
+  SPDY_BUG_IF(framer.GetFrameMaximumSize() < length_)
+      << "Frame length  " << length_
+      << " is longer than the maximum allowed length.";
+
+  offset_ += length_;
+  length_ = 0;
+
+  success &= WriteUInt24(length);
+  success &= WriteUInt8(SerializeFrameType(type));
+  success &= WriteUInt8(flags);
+  success &= WriteUInt32(stream_id);
+  DCHECK_EQ(framer.GetDataFrameMinimumSize(), length_);
+  return success;
+}
+
 bool SpdyFrameBuilder::WriteStringPiece16(const base::StringPiece& value) {
   if (value.size() > 0xffff) {
     DCHECK(false) << "Tried to write string with length > 16bit.";
     return false;
   }
 
   if (!WriteUInt16(static_cast<uint16_t>(value.size()))) {
     return false;
   }
 
@@ skipping 54 matching lines @@
 
   if (offset_ + length_ + length > capacity_) {
     DCHECK(false);
     return false;
   }
 
   return true;
 }
 
 }  // namespace net