Mark onIngress as noexcept in HTTP2Codec

Summary: Marking `onIngress()` as `noexcept` in HTTP2Codec for documentation purposes since the caller is invoking `onIngress()` in a `noexcept` context as well.

Reviewed By: hanidamlaj

Differential Revision: D74289818

fbshipit-source-id: bf5b2b6efe7330cf72e1125fe88250fa0afed4bd

Author: Joanna Jo

proxygen/lib/http/codec/HTTP2Codec.cpp

@@ -54,7 +54,7 @@ HTTP2Codec::~HTTP2Codec() {
 
 // HTTPCodec API
 
-size_t HTTP2Codec::onIngress(const folly::IOBuf& buf) {
+size_t HTTP2Codec::onIngress(const folly::IOBuf& buf) noexcept {
   // TODO: ensure only 1 parse at a time on stack.
   FOLLY_SCOPED_TRACE_SECTION("HTTP2Codec - onIngress");
 

proxygen/lib/http/codec/HTTP2Codec.h

@@ -46,7 +46,7 @@ class HTTP2Codec
     return userAgent_;
   }
 
-  size_t onIngress(const folly::IOBuf& buf) override;
+  size_t onIngress(const folly::IOBuf& buf) noexcept override;
   bool onIngressUpgradeMessage(const HTTPMessage& msg) override;
   size_t generateConnectionPreface(folly::IOBufQueue& writeBuf) override;
   void generateHeader(