gfe-relnote: n/a(code cleanup) enable -Wreturn-type compile option in
third_party/quic.

Fix code violations of this check and other fixes.

PiperOrigin-RevId: 257833581
Change-Id: I92a1b73f829f6d05d023e0b194e8e800d7f21bbf

http2/decoder/frame_decoder_state.cc

diff --git a/http2/decoder/frame_decoder_state.cc b/http2/decoder/frame_decoder_state.cc
index 5487997..479decb 100644
--- a/http2/decoder/frame_decoder_state.cc
+++ b/http2/decoder/frame_decoder_state.cc
@@ -56,7 +56,6 @@
                  << ", header: " << frame_header();
   DCHECK_EQ(remaining_payload_, 0u);
   DCHECK(IsPaddable()) << "header: " << frame_header();
-  DCHECK_GE(remaining_padding_, 0u);
   DCHECK(remaining_padding_ == 0 || frame_header().IsPadded())
       << "remaining_padding_=" << remaining_padding_
       << ", header: " << frame_header();

quic/core/qpack/qpack_instruction_decoder.cc

diff --git a/quic/core/qpack/qpack_instruction_decoder.cc b/quic/core/qpack/qpack_instruction_decoder.cc
index 2076fa7..187894d 100644
--- a/quic/core/qpack/qpack_instruction_decoder.cc
+++ b/quic/core/qpack/qpack_instruction_decoder.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <utility>
 
+#include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
 
 namespace quic {
@@ -172,6 +173,9 @@
     case http2::DecodeStatus::kDecodeError:
       OnError("Encoded integer too large.");
       return bytes_consumed;
+    default:
+      QUIC_BUG << "Unknown decode status " << status;
+      return bytes_consumed;
   }
 }
 
@@ -197,6 +201,9 @@
     case http2::DecodeStatus::kDecodeError:
       OnError("Encoded integer too large.");
       return bytes_consumed;
+    default:
+      QUIC_BUG << "Unknown decode status " << status;
+      return bytes_consumed;
   }
 }