gfe-relnote: Let GFE be able to use FIFO write scheduler in QUIC and enable it via a connection option FIFO. Protected by gfe2_reloadable_flag_quic_use_fifo_write_scheduler.

PiperOrigin-RevId: 261676376
Change-Id: I74a4d92ad6d612c565eaa1e38186738988d02fe5

spdy/core/spdy_protocol.cc

diff --git a/spdy/core/spdy_protocol.cc b/spdy/core/spdy_protocol.cc
index d9b642f..9094b47 100644
--- a/spdy/core/spdy_protocol.cc
+++ b/spdy/core/spdy_protocol.cc
@@ -229,6 +229,20 @@
   return "UNKNOWN_ERROR_CODE";
 }
 
+const char* WriteSchedulerTypeToString(WriteSchedulerType type) {
+  switch (type) {
+    case WriteSchedulerType::LIFO:
+      return "LIFO";
+    case WriteSchedulerType::SPDY:
+      return "SPDY";
+    case WriteSchedulerType::HTTP2:
+      return "HTTP2";
+    case WriteSchedulerType::FIFO:
+      return "FIFO";
+  }
+  return "UNKNOWN";
+}
+
 size_t GetNumberRequiredContinuationFrames(size_t size) {
   DCHECK_GT(size, kHttp2MaxControlFrameSendSize);
   size_t overflow = size - kHttp2MaxControlFrameSendSize;

spdy/core/spdy_protocol.h

diff --git a/spdy/core/spdy_protocol.h b/spdy/core/spdy_protocol.h
index 2d2ce96..2a521ab 100644
--- a/spdy/core/spdy_protocol.h
+++ b/spdy/core/spdy_protocol.h
@@ -203,6 +203,7 @@
          // https://www.chromium.org/spdy/spdy-protocol/spdy-protocol-draft3-1#TOC-2.3.3-Stream-priority.
   HTTP2,  // Uses HTTP2 (tree-style) priority described in
           // https://tools.ietf.org/html/rfc7540#section-5.3.
+  FIFO,   // Stream with the smallest stream ID has the highest priority.
 };
 
 // A SPDY priority is a number between 0 and 7 (inclusive).
@@ -284,6 +285,9 @@
 // for logging/debugging.
 const char* ErrorCodeToString(SpdyErrorCode error_code);
 
+// Serialize |type| to string for logging/debugging.
+const char* WriteSchedulerTypeToString(WriteSchedulerType type);
+
 // Minimum size of a frame, in octets.
 const size_t kFrameMinimumSize = kFrameHeaderSize;