Add a SpdyFramer extension API implementation.

net/spdy/spdy_frame_builder.h

 // 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.
 
 #ifndef NET_SPDY_SPDY_FRAME_BUILDER_H_
 #define NET_SPDY_SPDY_FRAME_BUILDER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 36 matching lines @@
   // GetWriteableBuffer() above.
   bool Seek(size_t length);
 
   // Populates this frame with a HTTP2 frame prefix using length information
   // from |capacity_|. The given type must be a control frame type.
   bool BeginNewFrame(const SpdyFramer& framer,
                      SpdyFrameType type,
                      uint8_t flags,
                      SpdyStreamId stream_id);
 
-  // Populates this frame with a HTTP2 frame prefix with length information.
-  // The given type must be a control frame type.

[Bence, 2017/04/05 13:43:09]

This is incorrect: "control frame" means defined frame type other than HEADERS,
but in fact this method is also used for HEADER frames.

+  // Populates this frame with a HTTP2 frame prefix with type and length
+  // information.  |type| must be a defined type.
   bool BeginNewFrame(const SpdyFramer& framer,
                      SpdyFrameType type,
                      uint8_t flags,
                      SpdyStreamId stream_id,
                      size_t length);
 
+  // Populates this frame with a HTTP2 frame prefix with type and length
+  // information.  |raw_frame_type| must not be a defined frame type.
+  bool BeginNewExtensionFrame(const SpdyFramer& framer,
+                              uint8_t raw_frame_type,
+                              uint8_t flags,
+                              SpdyStreamId stream_id,
+                              size_t length);
+
   // Takes the buffer from the SpdyFrameBuilder.
   SpdySerializedFrame take() {
     SPDY_BUG_IF(output_ != nullptr) << "ZeroCopyOutputBuffer is used to build "
                                     << "frames. take() shouldn't be called";
     SPDY_BUG_IF(kMaxFrameSizeLimit < length_)
         << "Frame length " << length_
         << " is longer than the maximum possible allowed length.";
     SpdySerializedFrame rv(buffer_.release(), length(), true);
     capacity_ = 0;
     length_ = 0;
@@ skipping 33 matching lines @@
   // The framer parameter is used to determine version-specific location and
   // size information of the length field to be written, and must be initialized
   // with the correct version for the frame being written.
   bool OverwriteLength(const SpdyFramer& framer, size_t length);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(SpdyFrameBuilderTest, GetWritableBuffer);
   FRIEND_TEST_ALL_PREFIXES(SpdyFrameBuilderTest, GetWritableOutput);
   FRIEND_TEST_ALL_PREFIXES(SpdyFrameBuilderTest, GetWritableOutputNegative);
 
+  // Populates this frame with a HTTP2 frame prefix with type and length
+  // information.
+  bool BeginNewFrameInternal(const SpdyFramer& framer,
+                             uint8_t raw_frame_type,
+                             uint8_t flags,
+                             SpdyStreamId stream_id,
+                             size_t length);
+
   // Returns a writeable buffer of given size in bytes, to be appended to the
   // currently written frame. Does bounds checking on length but does not
   // increment the underlying iterator. To do so, consumers should subsequently
   // call Seek().
   // In general, consumers should use Write*() calls instead of this.
   // Returns NULL on failure.
   char* GetWritableBuffer(size_t length);
   char* GetWritableOutput(size_t desired_length, size_t* actual_length);
 
   // Checks to make sure that there is an appropriate amount of space for a
@@ skipping 16 matching lines @@
   const size_t kLengthFieldLength = 3;
   char* start_of_current_frame_ = nullptr;
   size_t bytes_of_length_written_in_first_block_ = kLengthFieldLength;
   // In case length of a new frame is cross blocks.
   char* start_of_current_frame_in_next_block_ = nullptr;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_FRAME_BUILDER_H_