perf: prefer base::StringPiece over std::string for build-time strings (#38717)

* perf: use base::StringPiece in InclusionStatusToString()

The strings are all build-time constants and this is a private function

* perf: use base::StringPiece in ErrorCodeToString()

The strings are all build-time constants and this is a private function

* perf: use base::StringPiece in MessageSourceToString()

The strings are all build-time constants and this is a private function

* perf: use base::StringPiece in CursorTypeToString()

The strings are all build-time constants and this is a private function

* perf: use base::StringPiece in MediaStreamTypeToString()

The strings are all build-time constants and this is a private function

* perf: use base::StringPiece in ModifiersToArray()

The strings are all build-time constants and this is a private function

* perf: use base::StringPiece in WebFrameRenderer::MaybeGetRenderFrame()

The strings are all build-time constants and this is a private function

shell/browser/api/electron_api_protocol.cc

@@ -167,7 +167,7 @@ const char* const kBuiltinSchemes[] = {
 };
 
 // Convert error code to string.
-std::string ErrorCodeToString(ProtocolError error) {
+constexpr base::StringPiece ErrorCodeToString(ProtocolError error) {
   switch (error) {
     case ProtocolError::kRegistered:
       return "The scheme has been registered";