[SPDY] Incorporate latest framing changes from HTTP2 into SPDY 4 as SPDY 4a2.

Removes support for SPDY 4a1.

Remove --enable-spdy4 flag for now (until we get test
coverage).

This lands server change 45362310.

BUG=230124
TBR=jam@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14189003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@200342 0039d316-1c4b-4281-b951-d872f2087c98

21 files changed, 246 insertions, 162 deletions

diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 4146ca3..bcb5c98 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -6691,12 +6691,6 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_DESCRIPTION" desc="Description for the flag to defer image decoding in WebKit.">
         Defer image decoding operations in WebKit until painting.
       </message>
-      <message name="IDS_FLAGS_ENABLE_SPDY4A1_NAME" desc="Title for the flag to enable SPDY/4 alpha 1">
-        Enable SPDY/4 alpha 1
-      </message>
-      <message name="IDS_FLAGS_ENABLE_SPDY4A1_DESCRIPTION" desc="Description for the flag to enable SPDY/4 alpha 1.">
-        Enable experimental SPDY/4 alpha 1. Note that this also enables SPDY/3.1.
-      </message>
       <message name="IDS_FLAGS_ENABLE_ASYNC_DNS_NAME" desc="Title for the flag to enable asynchronous DNS client.">
         Built-in Asynchronous DNS
       </message>
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 47e19ff..5f0de4a 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -672,13 +672,6 @@ const Experiment kExperiments[] = {
     SINGLE_VALUE_TYPE(switches::kEnableAutologin)
   },
   {
-    "enable-spdy4a1",
-    IDS_FLAGS_ENABLE_SPDY4A1_NAME,
-    IDS_FLAGS_ENABLE_SPDY4A1_DESCRIPTION,
-    kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableSpdy4a1)
-  },
-  {
     "enable-async-dns",
     IDS_FLAGS_ENABLE_ASYNC_DNS_NAME,
     IDS_FLAGS_ENABLE_ASYNC_DNS_DESCRIPTION,
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 0631571..568734b 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -657,8 +657,6 @@ void IOThread::InitializeNetworkOptions(const CommandLine& command_line) {
     std::string spdy_mode =
         command_line.GetSwitchValueASCII(switches::kUseSpdy);
     EnableSpdy(spdy_mode);
-  } else if (command_line.HasSwitch(switches::kEnableSpdy4a1)) {
-    net::HttpStreamFactory::EnableNpnSpdy4a1();
   } else if (command_line.HasSwitch(switches::kDisableSpdy31)) {
     net::HttpStreamFactory::EnableNpnSpdy3();
   } else if (command_line.HasSwitch(switches::kEnableNpn)) {
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 8efec7a..bcb4e70 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -647,9 +647,6 @@ const char kEnableSdch[]                    = "enable-sdch";
 // Disable SPDY/3.1. This is a temporary testing flag.
 const char kDisableSpdy31[]                 = "disable-spdy31";
 
-// Enable SPDY/4 alpha 1. This is a temporary testing flag.
-const char kEnableSpdy4a1[]                 = "enable-spdy4a1";
-
 // Enable SPDY CREDENTIAL frame support.  This is a temporary testing flag.
 const char kEnableSpdyCredentialFrames[]    = "enable-spdy-credential-frames";
 
diff --git a/chrome/common/chrome_switches.h b/chrome/common/chrome_switches.h
index d6a536f..094406d 100644
--- a/chrome/common/chrome_switches.h
+++ b/chrome/common/chrome_switches.h
@@ -182,7 +182,6 @@ extern const char kEnableQuic[];
 extern const char kEnableResourceContentSettings[];
 extern const char kEnableSdch[];
 extern const char kDisableSpdy31[];
-extern const char kEnableSpdy4a1[];
 extern const char kEnableSpdyCredentialFrames[];
 extern const char kEnableSpellingAutoCorrect[];
 extern const char kEnableStackedTabStrip[];
diff --git a/net/http/http_server_properties.cc b/net/http/http_server_properties.cc
index 48b21ac..81a0e98 100644
--- a/net/http/http_server_properties.cc
+++ b/net/http/http_server_properties.cc
@@ -17,7 +17,7 @@ const char* const kAlternateProtocolStrings[] = {
   "npn-spdy/2",
   "npn-spdy/3",
   "npn-spdy/3.1",
-  "npn-spdy/4a1",
+  "npn-spdy/4a2",
   "quic"
 };
 const char kBrokenAlternateProtocol[] = "Broken";
diff --git a/net/http/http_server_properties.h b/net/http/http_server_properties.h
index 28a608f..e1fb9db 100644
--- a/net/http/http_server_properties.h
+++ b/net/http/http_server_properties.h
@@ -20,7 +20,7 @@ enum AlternateProtocol {
   NPN_SPDY_2,
   NPN_SPDY_3,
   NPN_SPDY_3_1,
-  NPN_SPDY_4a1,
+  NPN_SPDY_4A2,
   QUIC,
   NUM_ALTERNATE_PROTOCOLS,
   ALTERNATE_PROTOCOL_BROKEN,  // The alternate protocol is known to be broken.
diff --git a/net/http/http_stream_factory.cc b/net/http/http_stream_factory.cc
index 8432fb6..05114ba 100644
--- a/net/http/http_stream_factory.cc
+++ b/net/http/http_stream_factory.cc
@@ -180,18 +180,6 @@ void HttpStreamFactory::EnableNpnSpdy31() {
 }
 
 // static
-void HttpStreamFactory::EnableNpnSpdy4a1() {
-  set_use_alternate_protocols(true);
-  std::vector<std::string> next_protos;
-  next_protos.push_back("http/1.1");
-  next_protos.push_back("spdy/2");
-  next_protos.push_back("spdy/3");
-  next_protos.push_back("spdy/3.1");
-  next_protos.push_back("spdy/4a1");
-  SetNextProtos(next_protos);
-}
-
-// static
 void HttpStreamFactory::SetNextProtos(const std::vector<std::string>& value) {
   if (!next_protos_)
     next_protos_ = new std::vector<std::string>;
@@ -212,8 +200,8 @@ void HttpStreamFactory::SetNextProtos(const std::vector<std::string>& value) {
       enabled_protocols_[NPN_SPDY_3] = true;
     } else if (value[i] == "spdy/3.1") {
       enabled_protocols_[NPN_SPDY_3_1] = true;
-    } else if (value[i] == "spdy/4a1") {
-      enabled_protocols_[NPN_SPDY_4a1] = true;
+    } else if (value[i] == "spdy/4a2") {
+      enabled_protocols_[NPN_SPDY_4A2] = true;
     } else if (value[i] == "quic") {
       enabled_protocols_[QUIC] = true;
     }
diff --git a/net/http/http_stream_factory.h b/net/http/http_stream_factory.h
index c131897..eaadcc7 100644
--- a/net/http/http_stream_factory.h
+++ b/net/http/http_stream_factory.h
@@ -246,10 +246,6 @@ class NET_EXPORT HttpStreamFactory {
   // supported via NPN.
   static void EnableNpnSpdy31();
 
-  // Sets http/1.1, spdy/2, spdy/3, spdy/3.1, and spdy/4a1 as the
-  // protocols supported via NPN.
-  static void EnableNpnSpdy4a1();
-
   // Sets the protocols supported by NPN (next protocol negotiation) during the
   // SSL handshake as well as by HTTP Alternate-Protocol.
   static void SetNextProtos(const std::vector<std::string>& value);
diff --git a/net/socket/next_proto.h b/net/socket/next_proto.h
index 9d5b911..32fbff7 100644
--- a/net/socket/next_proto.h
+++ b/net/socket/next_proto.h
@@ -21,8 +21,8 @@ enum NextProto {
   kProtoSPDY21 = 4,
   kProtoSPDY3 = 5,
   kProtoSPDY31 = 6,
-  kProtoSPDY4a1 = 7,
-  kProtoSPDYMaximumVersion = kProtoSPDY4a1,
+  kProtoSPDY4a2 = 7,
+  kProtoSPDYMaximumVersion = kProtoSPDY4a2,
 
   kProtoMaximumVersion = 7,
 };
diff --git a/net/socket/ssl_client_socket.cc b/net/socket/ssl_client_socket.cc
index 371f790..fa1b6af 100644
--- a/net/socket/ssl_client_socket.cc
+++ b/net/socket/ssl_client_socket.cc
@@ -28,8 +28,8 @@ NextProto SSLClientSocket::NextProtoFromString(
     return kProtoSPDY3;
   } else if (proto_string == "spdy/3.1") {
     return kProtoSPDY31;
-  } else if (proto_string == "spdy/4a1") {
-    return kProtoSPDY4a1;
+  } else if (proto_string == "spdy/4a2") {
+    return kProtoSPDY4a2;
   } else {
     return kProtoUnknown;
   }
@@ -48,8 +48,8 @@ const char* SSLClientSocket::NextProtoToString(NextProto next_proto) {
       return "spdy/3";
     case kProtoSPDY31:
       return "spdy/3.1";
-    case kProtoSPDY4a1:
-      return "spdy/4a1";
+    case kProtoSPDY4a2:
+      return "spdy/4a2";
     default:
       break;
   }
diff --git a/net/spdy/spdy_frame_builder.cc b/net/spdy/spdy_frame_builder.cc
index 73b9144..9e779ff 100644
--- a/net/spdy/spdy_frame_builder.cc
+++ b/net/spdy/spdy_frame_builder.cc
@@ -62,19 +62,13 @@ bool SpdyFrameBuilder::WriteControlFrameHeader(const SpdyFramer& framer,
                                                uint8 flags) {
   DCHECK_GE(type, FIRST_CONTROL_TYPE);
   DCHECK_LE(type, LAST_CONTROL_TYPE);
+  DCHECK_GT(4, framer.protocol_version());
   bool success = true;
-  if (framer.protocol_version() < 4) {
-    FlagsAndLength flags_length = CreateFlagsAndLength(
-        flags, capacity_ - framer.GetControlFrameHeaderSize());
-    success &= WriteUInt16(kControlFlagMask | framer.protocol_version());
-    success &= WriteUInt16(type);
-    success &= WriteBytes(&flags_length, sizeof(flags_length));
-  } else {
-    DCHECK_GT(1u<<16, capacity_);  // Make sure length fits in 2B.
-    success &= WriteUInt16(capacity_);
-    success &= WriteUInt8(type);
-    success &= WriteUInt8(flags);
-  }
+  FlagsAndLength flags_length = CreateFlagsAndLength(
+      flags, capacity_ - framer.GetControlFrameHeaderSize());
+  success &= WriteUInt16(kControlFlagMask | framer.protocol_version());
+  success &= WriteUInt16(type);
+  success &= WriteBytes(&flags_length, sizeof(flags_length));
   DCHECK_EQ(framer.GetControlFrameHeaderSize(), length());
   return success;
 }
@@ -82,24 +76,37 @@ bool SpdyFrameBuilder::WriteControlFrameHeader(const SpdyFramer& framer,
 bool SpdyFrameBuilder::WriteDataFrameHeader(const SpdyFramer& framer,
                                             SpdyStreamId stream_id,
                                             SpdyDataFlags flags) {
+  if (framer.protocol_version() >= 4) {
+    return WriteFramePrefix(framer, DATA, flags, stream_id);
+  }
   DCHECK_EQ(0u, stream_id & ~kStreamIdMask);
   bool success = true;
-  if (framer.protocol_version() < 4) {
-    success &= WriteUInt32(stream_id);
-    size_t length_field = capacity_ - framer.GetDataFrameMinimumSize();
-    DCHECK_EQ(0u, length_field & ~static_cast<size_t>(kLengthMask));
-    FlagsAndLength flags_length;
-    flags_length.length_ = htonl(length_field);
-    DCHECK_EQ(0, flags & ~kDataFlagsMask);
-    flags_length.flags_[0] = flags;
-    success &= WriteBytes(&flags_length, sizeof(flags_length));
-  } else {
-    DCHECK_GT(1u<<16, capacity_);  // Make sure length fits in 2B.
-    success &= WriteUInt16(capacity_);
-    success &= WriteUInt8(0);
-    success &= WriteUInt8(flags);
-    success &= WriteUInt32(stream_id);
-  }
+  success &= WriteUInt32(stream_id);
+  size_t length_field = capacity_ - framer.GetDataFrameMinimumSize();
+  DCHECK_EQ(0u, length_field & ~static_cast<size_t>(kLengthMask));
+  FlagsAndLength flags_length;
+  flags_length.length_ = htonl(length_field);
+  DCHECK_EQ(0, flags & ~kDataFlagsMask);
+  flags_length.flags_[0] = flags;
+  success &= WriteBytes(&flags_length, sizeof(flags_length));
+  DCHECK_EQ(framer.GetDataFrameMinimumSize(), length());
+  return success;
+}
+
+bool SpdyFrameBuilder::WriteFramePrefix(const SpdyFramer& framer,
+                                        SpdyFrameType type,
+                                        uint8 flags,
+                                        SpdyStreamId stream_id) {
+  DCHECK_LE(DATA, type);
+  DCHECK_GE(LAST_CONTROL_TYPE, type);
+  DCHECK_EQ(0u, stream_id & ~kStreamIdMask);
+  DCHECK_LE(4, framer.protocol_version());
+  bool success = true;
+  DCHECK_GT(1u<<16, capacity_);  // Make sure length fits in 2B.
+  success &= WriteUInt16(capacity_);
+  success &= WriteUInt8(type);
+  success &= WriteUInt8(flags);
+  success &= WriteUInt32(stream_id);
   DCHECK_EQ(framer.GetDataFrameMinimumSize(), length());
   return success;
 }
diff --git a/net/spdy/spdy_frame_builder.h b/net/spdy/spdy_frame_builder.h
index 7f9b3b1..825254d 100644
--- a/net/spdy/spdy_frame_builder.h
+++ b/net/spdy/spdy_frame_builder.h
@@ -50,6 +50,7 @@ class NET_EXPORT_PRIVATE SpdyFrameBuilder {
   // Populates this frame with a SPDY control frame header using
   // version-specific information from the |framer| and length information from
   // capacity_. The given type must be a control frame type.
+  // Used only for SPDY versions <4.
   bool WriteControlFrameHeader(const SpdyFramer& framer,
                                SpdyFrameType type,
                                uint8 flags);
@@ -60,6 +61,15 @@ class NET_EXPORT_PRIVATE SpdyFrameBuilder {
                             SpdyStreamId stream_id,
                             SpdyDataFlags flags);
 
+  // Populates this frame with a SPDY4/HTTP2 frame prefix using
+  // version-specific information from the |framer| and length information from
+  // capacity_. The given type must be a control frame type.
+  // Used only for SPDY versions >=4.
+  bool WriteFramePrefix(const SpdyFramer& framer,
+                        SpdyFrameType type,
+                        uint8 flags,
+                        SpdyStreamId stream_id);
+
   // Takes the buffer from the SpdyFrameBuilder.
   SpdyFrame* take() {
     SpdyFrame* rv = new SpdyFrame(buffer_.release(), length_, true);
diff --git a/net/spdy/spdy_frame_builder_test.cc b/net/spdy/spdy_frame_builder_test.cc
index eeea2b6..65d9b05 100644
--- a/net/spdy/spdy_frame_builder_test.cc
+++ b/net/spdy/spdy_frame_builder_test.cc
@@ -53,7 +53,11 @@ TEST_P(SpdyFrameBuilderTest, RewriteLength) {
   SettingsMap settings;
   scoped_ptr<SpdyFrame> expected(framer.CreateSettings(settings));
   SpdyFrameBuilder builder(expected->size() + 1);
-  builder.WriteControlFrameHeader(framer, SETTINGS, 0);
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(framer, SETTINGS, 0);
+  } else {
+    builder.WriteFramePrefix(framer, SETTINGS, 0, 0);
+  }
   builder.WriteUInt32(0); // Write the number of settings.
   EXPECT_TRUE(builder.GetWritableBuffer(1) != NULL);
   builder.RewriteLength(framer);
diff --git a/net/spdy/spdy_framer.cc b/net/spdy/spdy_framer.cc
index 125b6cc..b3954484 100644
--- a/net/spdy/spdy_framer.cc
+++ b/net/spdy/spdy_framer.cc
@@ -167,7 +167,7 @@ size_t SpdyFramer::GetControlFrameHeaderSize() const {
     case 3:
       return 8;
     case 4:
-      return 4;
+      return 8;
   }
   LOG(DFATAL) << "Unhandled SPDY version.";
   return 0;
@@ -175,16 +175,27 @@ size_t SpdyFramer::GetControlFrameHeaderSize() const {
 
 size_t SpdyFramer::GetSynStreamMinimumSize() const {
   // Size, in bytes, of a SYN_STREAM frame not including the variable-length
-  // name-value block. Calculated as:
-  // control frame header + 2 * 4 (stream IDs) + 1 (priority) + 1 (slot)
-  return GetControlFrameHeaderSize() + 10;
+  // name-value block.
+  if (spdy_version_ < 4) {
+    // Calculated as:
+    // control frame header + 2 * 4 (stream IDs) + 1 (priority) + 1 (slot)
+    return GetControlFrameHeaderSize() + 10;
+  } else {
+    // Calculated as:
+    // frame prefix + 4 (associated stream ID) + 1 (priority) + 1 (slot)
+    return GetControlFrameHeaderSize() + 6;
+  }
 }
 
 size_t SpdyFramer::GetSynReplyMinimumSize() const {
   // Size, in bytes, of a SYN_REPLY frame not including the variable-length
-  // name-value block. Calculated as:
-  // control frame header + 4 (stream ID)
-  size_t size = GetControlFrameHeaderSize() + 4;
+  // name-value block.
+  size_t size = GetControlFrameHeaderSize();
+  if (spdy_version_ < 4) {
+    // Calculated as:
+    // control frame header + 4 (stream IDs)
+    size += 4;
+  }
 
   // In SPDY 2, there were 2 unused bytes before payload.
   if (protocol_version() < 3) {
@@ -195,9 +206,16 @@ size_t SpdyFramer::GetSynReplyMinimumSize() const {
 }
 
 size_t SpdyFramer::GetRstStreamSize() const {
-  // Size, in bytes, of a RST_STREAM frame. Calculated as:
-  // control frame header + 4 (stream id) + 4 (status code)
-  return GetControlFrameHeaderSize() + 8;
+  // Size, in bytes, of a RST_STREAM frame.
+  if (spdy_version_ < 4) {
+    // Calculated as:
+    // control frame header + 4 (stream id) + 4 (status code)
+    return GetControlFrameHeaderSize() + 8;
+  } else {
+    // Calculated as:
+    // frame prefix + 4 (status code)
+    return GetControlFrameHeaderSize() + 4;
+  }
 }
 
 size_t SpdyFramer::GetSettingsMinimumSize() const {
@@ -227,10 +245,14 @@ size_t SpdyFramer::GetGoAwaySize() const {
 }
 
 size_t SpdyFramer::GetHeadersMinimumSize() const  {
-  // Size, in bytes, of a HEADERS frame not including the variable-length
-  // name-value block. Calculated as:
-  // control frame header + 4 (stream ID)
-  size_t size = GetControlFrameHeaderSize() + 4;
+  // Size, in bytes, of a SYN_REPLY frame not including the variable-length
+  // name-value block.
+  size_t size = GetControlFrameHeaderSize();
+  if (spdy_version_ < 4) {
+    // Calculated as:
+    // control frame header + 4 (stream IDs)
+    size += 4;
+  }
 
   // In SPDY 2, there were 2 unused bytes before payload.
   if (protocol_version() < 3) {
@@ -241,9 +263,16 @@ size_t SpdyFramer::GetHeadersMinimumSize() const  {
 }
 
 size_t SpdyFramer::GetWindowUpdateSize() const {
-  // Size, in bytes, of this WINDOW_UPDATE frame. Calculated as:
-  // control frame header + 4 (stream id) + 4 (delta)
-  return GetControlFrameHeaderSize() + 8;
+  // Size, in bytes, of a WINDOW_UPDATE frame.
+  if (spdy_version_ < 4) {
+    // Calculated as:
+    // control frame header + 4 (stream id) + 4 (delta)
+    return GetControlFrameHeaderSize() + 8;
+  } else {
+    // Calculated as:
+    // frame prefix + 4 (delta)
+    return GetControlFrameHeaderSize() + 4;
+  }
 }
 
 size_t SpdyFramer::GetCredentialMinimumSize() const {
@@ -542,7 +571,6 @@ size_t SpdyFramer::ProcessCommonHeader(const char* data, size_t len) {
     remaining_data_length_ = length_field;
     current_frame_length_ = remaining_data_length_ + reader->GetBytesConsumed();
   } else {
-    // TODO(hkhalil): Avoid re-reading fields as possible for DATA frames?
     version = protocol_version();
     uint16 length_field = 0;
     bool successful_read = reader->ReadUInt16(&length_field);
@@ -560,23 +588,9 @@ size_t SpdyFramer::ProcessCommonHeader(const char* data, size_t len) {
     successful_read = reader->ReadUInt8(&current_frame_flags_);
     DCHECK(successful_read);
 
-    if (!is_control_frame) {
-      // We may not have the entirety of the DATA frame header.
-      if (current_frame_buffer_length_ < GetDataFrameMinimumSize()) {
-        size_t bytes_desired =
-            GetDataFrameMinimumSize() - current_frame_buffer_length_;
-        UpdateCurrentFrameBuffer(&data, &len, bytes_desired);
-        if (current_frame_buffer_length_ < GetDataFrameMinimumSize()) {
-          return original_len - len;
-        }
-      }
-      // Construct a new SpdyFrameReader aware of the new frame length.
-      reader.reset(new SpdyFrameReader(current_frame_buffer_.get(),
-                                       current_frame_buffer_length_));
-      reader->Seek(GetControlFrameHeaderSize());
-      successful_read = reader->ReadUInt31(&current_frame_stream_id_);
-      DCHECK(successful_read);
-    }
+    successful_read = reader->ReadUInt31(&current_frame_stream_id_);
+    DCHECK(successful_read);
+
     remaining_data_length_ = current_frame_length_ - reader->GetBytesConsumed();
   }
   DCHECK_EQ(is_control_frame ? GetControlFrameHeaderSize()
@@ -1042,8 +1056,11 @@ size_t SpdyFramer::ProcessControlFrameBeforeHeaderBlock(const char* data,
     switch (current_frame_type_) {
       case SYN_STREAM:
         {
-          bool successful_read = reader.ReadUInt31(&current_frame_stream_id_);
-          DCHECK(successful_read);
+          bool successful_read = true;
+          if (spdy_version_ < 4) {
+            successful_read = reader.ReadUInt31(&current_frame_stream_id_);
+            DCHECK(successful_read);
+          }
 
           SpdyStreamId associated_to_stream_id = kInvalidStream;
           successful_read = reader.ReadUInt31(&associated_to_stream_id);
@@ -1082,8 +1099,11 @@ size_t SpdyFramer::ProcessControlFrameBeforeHeaderBlock(const char* data,
       case HEADERS:
         // SYN_REPLY and HEADERS are the same, save for the visitor call.
         {
-          bool successful_read = reader.ReadUInt31(&current_frame_stream_id_);
-          DCHECK(successful_read);
+          bool successful_read = true;
+          if (spdy_version_ < 4) {
+            successful_read = reader.ReadUInt31(&current_frame_stream_id_);
+            DCHECK(successful_read);
+          }
           if (protocol_version() < 3) {
             // SPDY 2 had two unused bytes here. Seek past them.
             reader.Seek(2);
@@ -1288,9 +1308,12 @@ size_t SpdyFramer::ProcessControlFramePayload(const char* data, size_t len) {
           break;
         case WINDOW_UPDATE: {
             uint32 delta_window_size = 0;
-            bool successful_read = reader.ReadUInt31(&current_frame_stream_id_);
-            DCHECK(successful_read);
-            successful_read = reader.ReadUInt31(&delta_window_size);
+            bool successful_read = true;
+            if (spdy_version_ < 4) {
+              successful_read = reader.ReadUInt31(&current_frame_stream_id_);
+              DCHECK(successful_read);
+            }
+            successful_read = reader.ReadUInt32(&delta_window_size);
             DCHECK(successful_read);
             DCHECK(reader.IsDoneReading());
             visitor_->OnWindowUpdate(current_frame_stream_id_,
@@ -1298,8 +1321,11 @@ size_t SpdyFramer::ProcessControlFramePayload(const char* data, size_t len) {
           }
           break;
         case RST_STREAM: {
-            bool successful_read = reader.ReadUInt32(&current_frame_stream_id_);
-            DCHECK(successful_read);
+            bool successful_read = true;
+            if (spdy_version_ < 4) {
+              successful_read = reader.ReadUInt31(&current_frame_stream_id_);
+              DCHECK(successful_read);
+            }
             SpdyRstStreamStatus status = RST_STREAM_INVALID;
             uint32 status_raw = status;
             successful_read = reader.ReadUInt32(&status_raw);
@@ -1511,8 +1537,15 @@ SpdySerializedFrame* SpdyFramer::SerializeSynStream(
       + GetSerializedLength(syn_stream.name_value_block());
 
   SpdyFrameBuilder builder(size);
-  builder.WriteControlFrameHeader(*this, SYN_STREAM, flags);
-  builder.WriteUInt32(syn_stream.stream_id());
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, SYN_STREAM, flags);
+    builder.WriteUInt32(syn_stream.stream_id());
+  } else {
+    builder.WriteFramePrefix(*this,
+                             SYN_STREAM,
+                             flags,
+                             syn_stream.stream_id());
+  }
   builder.WriteUInt32(syn_stream.associated_to_stream_id());
   uint8 priority = syn_stream.priority();
   if (priority > GetLowestPriority()) {
@@ -1559,8 +1592,15 @@ SpdySerializedFrame* SpdyFramer::SerializeSynReply(
       + GetSerializedLength(syn_reply.name_value_block());
 
   SpdyFrameBuilder builder(size);
-  builder.WriteControlFrameHeader(*this, SYN_REPLY, flags);
-  builder.WriteUInt32(syn_reply.stream_id());
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, SYN_REPLY, flags);
+    builder.WriteUInt32(syn_reply.stream_id());
+  } else {
+    builder.WriteFramePrefix(*this,
+                             SYN_REPLY,
+                             flags,
+                             syn_reply.stream_id());
+  }
   if (protocol_version() < 3) {
     builder.WriteUInt16(0);  // Unused.
   }
@@ -1580,8 +1620,15 @@ SpdyFrame* SpdyFramer::CreateRstStream(
 SpdySerializedFrame* SpdyFramer::SerializeRstStream(
     const SpdyRstStreamIR& rst_stream) const {
   SpdyFrameBuilder builder(GetRstStreamSize());
-  builder.WriteControlFrameHeader(*this, RST_STREAM, 0);
-  builder.WriteUInt32(rst_stream.stream_id());
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, RST_STREAM, 0);
+    builder.WriteUInt32(rst_stream.stream_id());
+  } else {
+    builder.WriteFramePrefix(*this,
+                             RST_STREAM,
+                             0,
+                             rst_stream.stream_id());
+  }
   builder.WriteUInt32(rst_stream.status());
   DCHECK_EQ(GetRstStreamSize(), builder.length());
   return builder.take();
@@ -1613,7 +1660,11 @@ SpdySerializedFrame* SpdyFramer::SerializeSettings(
   const size_t size = GetSettingsMinimumSize() + (values->size() * 8);
 
   SpdyFrameBuilder builder(size);
-  builder.WriteControlFrameHeader(*this, SETTINGS, flags);
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, SETTINGS, flags);
+  } else {
+    builder.WriteFramePrefix(*this, SETTINGS, flags, 0);
+  }
   builder.WriteUInt32(values->size());
   DCHECK_EQ(GetSettingsMinimumSize(), builder.length());
   for (SpdySettingsIR::ValueMap::const_iterator it = values->begin();
@@ -1642,7 +1693,11 @@ SpdyFrame* SpdyFramer::CreatePingFrame(uint32 unique_id) const {
 
 SpdySerializedFrame* SpdyFramer::SerializePing(const SpdyPingIR& ping) const {
   SpdyFrameBuilder builder(GetPingSize());
-  builder.WriteControlFrameHeader(*this, PING, 0);
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, PING, kNoFlags);
+  } else {
+    builder.WriteFramePrefix(*this, PING, 0, 0);
+  }
   builder.WriteUInt32(ping.id());
   DCHECK_EQ(GetPingSize(), builder.length());
   return builder.take();
@@ -1658,7 +1713,11 @@ SpdyFrame* SpdyFramer::CreateGoAway(
 SpdySerializedFrame* SpdyFramer::SerializeGoAway(
     const SpdyGoAwayIR& goaway) const {
   SpdyFrameBuilder builder(GetGoAwaySize());
-  builder.WriteControlFrameHeader(*this, GOAWAY, 0);
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, GOAWAY, kNoFlags);
+  } else {
+    builder.WriteFramePrefix(*this, GOAWAY, 0, 0);
+  }
   builder.WriteUInt32(goaway.last_good_stream_id());
   if (protocol_version() >= 3) {
     builder.WriteUInt32(goaway.status());
@@ -1697,8 +1756,15 @@ SpdySerializedFrame* SpdyFramer::SerializeHeaders(
       + GetSerializedLength(headers.name_value_block());
 
   SpdyFrameBuilder builder(size);
-  builder.WriteControlFrameHeader(*this, HEADERS, flags);
-  builder.WriteUInt32(headers.stream_id());
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, HEADERS, flags);
+    builder.WriteUInt32(headers.stream_id());
+  } else {
+    builder.WriteFramePrefix(*this,
+                             HEADERS,
+                             flags,
+                             headers.stream_id());
+  }
   if (protocol_version() < 3) {
     builder.WriteUInt16(0);  // Unused.
   }
@@ -1719,8 +1785,15 @@ SpdyFrame* SpdyFramer::CreateWindowUpdate(
 SpdySerializedFrame* SpdyFramer::SerializeWindowUpdate(
     const SpdyWindowUpdateIR& window_update) const {
   SpdyFrameBuilder builder(GetWindowUpdateSize());
-  builder.WriteControlFrameHeader(*this, WINDOW_UPDATE, kNoFlags);
-  builder.WriteUInt32(window_update.stream_id());
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, WINDOW_UPDATE, kNoFlags);
+    builder.WriteUInt32(window_update.stream_id());
+  } else {
+    builder.WriteFramePrefix(*this,
+                             WINDOW_UPDATE,
+                             kNoFlags,
+                             window_update.stream_id());
+  }
   builder.WriteUInt32(window_update.delta());
   DCHECK_EQ(GetWindowUpdateSize(), builder.length());
   return builder.take();
@@ -1751,7 +1824,11 @@ SpdySerializedFrame* SpdyFramer::SerializeCredential(
   }
 
   SpdyFrameBuilder builder(size);
-  builder.WriteControlFrameHeader(*this, CREDENTIAL, 0);
+  if (spdy_version_ < 4) {
+    builder.WriteControlFrameHeader(*this, CREDENTIAL, kNoFlags);
+  } else {
+    builder.WriteFramePrefix(*this, CREDENTIAL, kNoFlags, 0);
+  }
   builder.WriteUInt16(credential.slot());
   DCHECK_EQ(GetCredentialMinimumSize(), builder.length());
   builder.WriteStringPiece32(credential.proof());
diff --git a/net/spdy/spdy_framer_test.cc b/net/spdy/spdy_framer_test.cc
index 63e99a7..60d784a 100644
--- a/net/spdy/spdy_framer_test.cc
+++ b/net/spdy/spdy_framer_test.cc
@@ -692,9 +692,13 @@ TEST_P(SpdyFramerTest, OutOfOrderHeaders) {
 
   // Frame builder with plentiful buffer size.
   SpdyFrameBuilder frame(1024);
-  frame.WriteControlFrameHeader(framer, SYN_STREAM, CONTROL_FLAG_NONE);
+  if (spdy_version_ < 4) {
+    frame.WriteControlFrameHeader(framer, SYN_STREAM, CONTROL_FLAG_NONE);
+    frame.WriteUInt32(3);  // stream_id
+  } else {
+    frame.WriteFramePrefix(framer, SYN_STREAM, CONTROL_FLAG_NONE, 3);
+  }
 
-  frame.WriteUInt32(3);  // stream_id
   frame.WriteUInt32(0);  // Associated stream id
   frame.WriteUInt16(0);  // Priority.
 
@@ -746,7 +750,8 @@ TEST_P(SpdyFramerTest, CreateCredential) {
       'e',  'r',  't',
     };
     const unsigned char kV4FrameData[] = {
-      0x00, 0x37, 0x0A, 0x00,
+      0x00, 0x3b, 0x0A, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x00, 0x03, 0x00, 0x00,
       0x00, 0x05, 'p',  'r',
       'o',  'o',  'f',  0x00,
@@ -799,6 +804,7 @@ TEST_P(SpdyFramerTest, ParseCredentialFrameData) {
     };
     const unsigned char kV4FrameData[] = {
       0x00, 0x37, 0x0A, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x00, 0x03, 0x00, 0x00,
       0x00, 0x05, 'p',  'r',
       'o',  'o',  'f',  0x00,
@@ -844,9 +850,13 @@ TEST_P(SpdyFramerTest, DuplicateHeader) {
   SpdyFramer framer(spdy_version_);
   // Frame builder with plentiful buffer size.
   SpdyFrameBuilder frame(1024);
-  frame.WriteControlFrameHeader(framer, SYN_STREAM, CONTROL_FLAG_NONE);
+  if (spdy_version_ < 4) {
+    frame.WriteControlFrameHeader(framer, SYN_STREAM, CONTROL_FLAG_NONE);
+    frame.WriteUInt32(3);  // stream_id
+  } else {
+    frame.WriteFramePrefix(framer, SYN_STREAM, CONTROL_FLAG_NONE, 3);
+  }
 
-  frame.WriteUInt32(3);  // stream_id
   frame.WriteUInt32(0);  // associated stream id
   frame.WriteUInt16(0);  // Priority.
 
@@ -881,9 +891,13 @@ TEST_P(SpdyFramerTest, MultiValueHeader) {
   SpdyFramer framer(spdy_version_);
   // Frame builder with plentiful buffer size.
   SpdyFrameBuilder frame(1024);
-  frame.WriteControlFrameHeader(framer, SYN_STREAM, CONTROL_FLAG_NONE);
+  if (spdy_version_ < 4) {
+    frame.WriteControlFrameHeader(framer, SYN_STREAM, CONTROL_FLAG_NONE);
+    frame.WriteUInt32(3);  // stream_id
+  } else {
+    frame.WriteFramePrefix(framer, SYN_STREAM, CONTROL_FLAG_NONE, 3);
+  }
 
-  frame.WriteUInt32(3);  // stream_id
   frame.WriteUInt32(0);  // associated stream id
   frame.WriteUInt16(0);  // Priority.
 
@@ -2390,7 +2404,8 @@ TEST_P(SpdyFramerTest, CreateSettings) {
       0x0a, 0x0b, 0x0c, 0x0d,
     };
     const unsigned char kV4FrameData[] = {
-      0x00, 0x10, 0x04, 0x00,
+      0x00, 0x14, 0x04, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x01,
       0x01, 0x02, 0x03, 0x04,
       0x0a, 0x0b, 0x0c, 0x0d,
@@ -2433,7 +2448,8 @@ TEST_P(SpdyFramerTest, CreateSettings) {
       0xff, 0x00, 0x00, 0x04,
     };
     const unsigned char kV4FrameData[] = {
-      0x00, 0x28, 0x04, 0x00,
+      0x00, 0x2c, 0x04, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x04,
       0x00, 0x00, 0x00, 0x00,  // 1st Setting
       0x00, 0x00, 0x00, 0x01,
@@ -2463,7 +2479,8 @@ TEST_P(SpdyFramerTest, CreateSettings) {
       0x00, 0x00, 0x00, 0x00,
     };
     const unsigned char kV4FrameData[] = {
-      0x00, 0x08, 0x04, 0x00,
+      0x00, 0x0c, 0x04, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00,
     };
     scoped_ptr<SpdyFrame> frame(framer.CreateSettings(settings));
@@ -2486,7 +2503,8 @@ TEST_P(SpdyFramerTest, CreatePingFrame) {
       0x12, 0x34, 0x56, 0x78,
     };
     const unsigned char kV4FrameData[] = {
-      0x00, 0x08, 0x06, 0x00,
+      0x00, 0x0c, 0x06, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x12, 0x34, 0x56, 0x78,
     };
     scoped_ptr<SpdyFrame> frame(framer.CreatePingFrame(0x12345678u));
@@ -2515,7 +2533,8 @@ TEST_P(SpdyFramerTest, CreateGoAway) {
       0x00, 0x00, 0x00, 0x00,
     };
     const unsigned char kV4FrameData[] = {
-      0x00, 0x0c, 0x07, 0x00,
+      0x00, 0x10, 0x07, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00,
     };
@@ -2543,7 +2562,8 @@ TEST_P(SpdyFramerTest, CreateGoAway) {
       0x00, 0x00, 0x00, 0x02,
     };
     const unsigned char kV4FrameData[] = {
-      0x00, 0x0c, 0x07, 0x00,
+      0x00, 0x10, 0x07, 0x00,
+      0x00, 0x00, 0x00, 0x00,
       0x7f, 0xff, 0xff, 0xff,
       0x00, 0x00, 0x00, 0x02,
     };
@@ -3270,7 +3290,8 @@ TEST_P(SpdyFramerTest, ReadDuplicateSettings) {
     0x00, 0x00, 0x00, 0x03,
   };
   const unsigned char kV4FrameData[] = {
-    0x00, 0x20, 0x04, 0x00,
+    0x00, 0x24, 0x04, 0x00,
+    0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x03,
     0x00, 0x00, 0x00, 0x01,  // 1st Setting
     0x00, 0x00, 0x00, 0x02,
@@ -3320,7 +3341,8 @@ TEST_P(SpdyFramerTest, ReadOutOfOrderSettings) {
     0x00, 0x00, 0x00, 0x03,
   };
   const unsigned char kV4FrameData[] = {
-    0x00, 0x20, 0x04, 0x00,
+    0x00, 0x24, 0x04, 0x00,
+    0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x03,
     0x00, 0x00, 0x00, 0x02,  // 1st Setting
     0x00, 0x00, 0x00, 0x02,
@@ -3507,17 +3529,15 @@ TEST_P(SpdyFramerTest, SizesTest) {
   SpdyFramer framer(spdy_version_);
   EXPECT_EQ(8u, framer.GetDataFrameMinimumSize());
   if (IsSpdy4()) {
-    EXPECT_EQ(4u, framer.GetControlFrameHeaderSize());
-    EXPECT_EQ(14u, framer.GetSynStreamMinimumSize());
     EXPECT_EQ(8u, framer.GetSynReplyMinimumSize());
     EXPECT_EQ(12u, framer.GetRstStreamSize());
-    EXPECT_EQ(8u, framer.GetSettingsMinimumSize());
-    EXPECT_EQ(8u, framer.GetPingSize());
-    EXPECT_EQ(12u, framer.GetGoAwaySize());
+    EXPECT_EQ(12u, framer.GetSettingsMinimumSize());
+    EXPECT_EQ(12u, framer.GetPingSize());
+    EXPECT_EQ(16u, framer.GetGoAwaySize());
     EXPECT_EQ(8u, framer.GetHeadersMinimumSize());
     EXPECT_EQ(12u, framer.GetWindowUpdateSize());
-    EXPECT_EQ(6u, framer.GetCredentialMinimumSize());
-    EXPECT_EQ(4u, framer.GetFrameMinimumSize());
+    EXPECT_EQ(10u, framer.GetCredentialMinimumSize());
+    EXPECT_EQ(8u, framer.GetFrameMinimumSize());
     EXPECT_EQ(65535u, framer.GetFrameMaximumSize());
     EXPECT_EQ(65527u, framer.GetDataFrameMaximumPayload());
   } else {
@@ -4124,7 +4144,8 @@ TEST_P(SpdyFramerTest, GoAwayStreamIdBounds) {
     0x00, 0x00, 0x00, 0x00,
   };
   const unsigned char kV4FrameData[] = {
-    0x00, 0x0c, 0x07, 0x00,
+    0x00, 0x10, 0x07, 0x00,
+    0x00, 0x00, 0x00, 0x00,
     0xff, 0xff, 0xff, 0xff,
     0x00, 0x00, 0x00, 0x00,
   };
diff --git a/net/spdy/spdy_http_stream_spdy3_unittest.cc b/net/spdy/spdy_http_stream_spdy3_unittest.cc
index d849f28..76f7a99 100644
--- a/net/spdy/spdy_http_stream_spdy3_unittest.cc
+++ b/net/spdy/spdy_http_stream_spdy3_unittest.cc
@@ -394,7 +394,7 @@ TEST_F(SpdyHttpStreamSpdy3Test, SendChunkedPost) {
 }
 
 TEST_F(SpdyHttpStreamSpdy3Test, SendChunkedPost4) {
-  session_deps_.protocol = kProtoSPDY4a1;
+  session_deps_.protocol = kProtoSPDY4a2;
   RunSendChunkedPostTest(kSpdyVersion4);
 }
 
diff --git a/net/spdy/spdy_network_transaction_spdy3_unittest.cc b/net/spdy/spdy_network_transaction_spdy3_unittest.cc
index 0d7d732..121ccc9 100644
--- a/net/spdy/spdy_network_transaction_spdy3_unittest.cc
+++ b/net/spdy/spdy_network_transaction_spdy3_unittest.cc
@@ -152,7 +152,7 @@ class SpdyNetworkTransactionSpdy3Test
       next_protos.push_back("spdy/2");
       next_protos.push_back("spdy/3");
       next_protos.push_back("spdy/3.1");
-      next_protos.push_back("spdy/4a1");
+      next_protos.push_back("spdy/4a2");
 
       switch (test_type_) {
         case SPDYNPN:
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 67cf065..f143607 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -61,7 +61,7 @@ int NPNToSpdyVersion(NextProto next_proto) {
     case kProtoSPDY3:
     case kProtoSPDY31:
       return kSpdyVersion3;
-    case kProtoSPDY4a1:
+    case kProtoSPDY4a2:
       return kSpdyVersion4;
     default:
       NOTREACHED();
@@ -444,7 +444,7 @@ Error SpdySession::InitializeWithSocket(
   }
 
   DCHECK_GE(protocol, kProtoSPDY2);
-  DCHECK_LE(protocol, kProtoSPDY4a1);
+  DCHECK_LE(protocol, kProtoSPDY4a2);
   if (protocol >= kProtoSPDY31) {
     flow_control_state_ = FLOW_CONTROL_STREAM_AND_SESSION;
     session_send_window_size_ = kSpdySessionInitialWindowSize;
diff --git a/net/spdy/spdy_session_spdy3_unittest.cc b/net/spdy/spdy_session_spdy3_unittest.cc
index 723b473..a151501 100644
--- a/net/spdy/spdy_session_spdy3_unittest.cc
+++ b/net/spdy/spdy_session_spdy3_unittest.cc
@@ -2409,7 +2409,7 @@ TEST_F(SpdySessionSpdy3Test, ProtocolNegotiation31) {
 // NOTE(akalin): We are still figuring out the story for SPDY4 test
 // coverage.
 TEST_F(SpdySessionSpdy3Test, ProtocolNegotiation4) {
-  session_deps_.protocol = kProtoSPDY4a1;
+  session_deps_.protocol = kProtoSPDY4a2;
   session_deps_.host_resolver->set_synchronous_mode(true);
 
   MockConnect connect_data(SYNCHRONOUS, OK);
diff --git a/net/spdy/spdy_test_util_common.cc b/net/spdy/spdy_test_util_common.cc
index 678ce79..d422021 100644
--- a/net/spdy/spdy_test_util_common.cc
+++ b/net/spdy/spdy_test_util_common.cc
@@ -517,7 +517,7 @@ NextProto NextProtoFromSpdyVersion(int spdy_version) {
   case kSpdyVersion3:
     return kProtoSPDY3;
   case kSpdyVersion4:
-    return kProtoSPDY4a1;
+    return kProtoSPDY4a2;
   default:
     NOTREACHED();
     return kProtoUnknown;
@@ -532,7 +532,7 @@ int SpdyVersionFromNextProto(NextProto next_proto) {
   case kProtoSPDY3:
   case kProtoSPDY31:
     return kSpdyVersion3;
-  case kProtoSPDY4a1:
+  case kProtoSPDY4a2:
     return kSpdyVersion4;
   default:
     NOTREACHED();