Add Validation Check 1.5/n: Change HTTPMessageFilter::getFilterName() to std::string_view

Summary:
Change the return type of `HTTPMessageFilter::getFilterName()` from `const std::string&` to `std::string_view`.

Nicer more modern API.

Reviewed By: hanidamlaj

Differential Revision: D89774003

fbshipit-source-id: 0579efedc96d1c205bdf75688327fad13fba2c73

Author: Will Wang

third-party/proxygen/src/proxygen/lib/http/HTTPMessageFilters.h

@@ -14,6 +14,8 @@
 
 #include <proxygen/lib/http/sink/HTTPSink.h>
 
+#include <string_view>
+
 namespace proxygen {
 
 static const std::string kMessageFilterDefaultName_ = "Unknown";
@@ -103,7 +105,7 @@ class HTTPMessageFilter
     nextTransactionHandler_->onExTransaction(txn);
   }
 
-  [[nodiscard]] virtual const std::string& getFilterName() const noexcept {
+  [[nodiscard]] virtual std::string_view getFilterName() const noexcept {
     return kMessageFilterDefaultName_;
   }
 

third-party/proxygen/src/proxygen/lib/http/test/MockHTTPMessageFilter.h

@@ -61,7 +61,7 @@ class MockHTTPMessageFilter : public HTTPMessageFilter {
     nextOnHeadersComplete(std::move(msgU));
   }
 
-  const std::string& getFilterName() const noexcept override {
+  std::string_view getFilterName() const noexcept override {
     return kMockFilterName;
   }