Use struct parser for rate control trial.

Bug: webrtc:9883
Change-Id: I9ec7988da2e4d88bedd9b71cae00452f531980d6
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/148581
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Jonas Olsson <jonasolsson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28856}
diff --git a/rtc_base/experiments/struct_parameters_parser_unittest.cc b/rtc_base/experiments/struct_parameters_parser_unittest.cc
index 1e88f8c..69103bd 100644
--- a/rtc_base/experiments/struct_parameters_parser_unittest.cc
+++ b/rtc_base/experiments/struct_parameters_parser_unittest.cc
@@ -17,30 +17,25 @@
   double factor = 0.5;
   int retries = 5;
   bool ping = 0;
-  std::string hash = "a80";
   absl::optional<TimeDelta> duration;
   absl::optional<TimeDelta> latency = TimeDelta::ms(100);
-  static StructParametersParser<DummyConfig>* Parser();
+  std::unique_ptr<StructParametersParser> Parser();
 };
 
-StructParametersParser<DummyConfig>* DummyConfig::Parser() {
-  using C = DummyConfig;
+std::unique_ptr<StructParametersParser> DummyConfig::Parser() {
   // The empty comments ensures that each pair is on a separate line.
-  static auto parser = CreateStructParametersParser(
-      "e", [](C* c) { return &c->enabled; },   //
-      "f", [](C* c) { return &c->factor; },    //
-      "r", [](C* c) { return &c->retries; },   //
-      "p", [](C* c) { return &c->ping; },      //
-      "h", [](C* c) { return &c->hash; },      //
-      "d", [](C* c) { return &c->duration; },  //
-      "l", [](C* c) { return &c->latency; });  //
-  return parser.get();
+  return StructParametersParser::Create("e", &enabled,   //
+                                        "f", &factor,    //
+                                        "r", &retries,   //
+                                        "p", &ping,      //
+                                        "d", &duration,  //
+                                        "l", &latency);
 }
 }  // namespace
 
 TEST(StructParametersParserTest, ParsesValidParameters) {
-  DummyConfig exp =
-      DummyConfig::Parser()->Parse("e:1,f:-1.7,r:2,p:1,h:x7c,d:8,l:,");
+  DummyConfig exp;
+  exp.Parser()->Parse("e:1,f:-1.7,r:2,p:1,d:8,l:,");
   EXPECT_TRUE(exp.enabled);
   EXPECT_EQ(exp.factor, -1.7);
   EXPECT_EQ(exp.retries, 2);
@@ -50,35 +45,19 @@
 }
 
 TEST(StructParametersParserTest, UsesDefaults) {
-  DummyConfig exp = DummyConfig::Parser()->Parse("");
+  DummyConfig exp;
+  exp.Parser()->Parse("");
   EXPECT_FALSE(exp.enabled);
   EXPECT_EQ(exp.factor, 0.5);
   EXPECT_EQ(exp.retries, 5);
   EXPECT_EQ(exp.ping, false);
-  EXPECT_EQ(exp.hash, "a80");
-}
-
-TEST(StructParametersParserTest, EmptyDefaults) {
-  DummyConfig exp;
-  auto encoded = DummyConfig::Parser()->EncodeChanged(exp);
-  // Unchanged parameters are not encoded.
-  EXPECT_EQ(encoded, "");
 }
 
 TEST(StructParametersParserTest, EncodeAll) {
   DummyConfig exp;
-  auto encoded = DummyConfig::Parser()->EncodeAll(exp);
+  auto encoded = exp.Parser()->Encode();
   // All parameters are encoded.
-  EXPECT_EQ(encoded, "d:,e:false,f:0.5,h:a80,l:100 ms,p:false,r:5");
-}
-
-TEST(StructParametersParserTest, EncodeChanged) {
-  DummyConfig exp;
-  exp.ping = true;
-  exp.retries = 4;
-  auto encoded = DummyConfig::Parser()->EncodeChanged(exp);
-  // We expect the changed parameters to be encoded in alphabetical order.
-  EXPECT_EQ(encoded, "p:true,r:4");
+  EXPECT_EQ(encoded, "e:false,f:0.5,r:5,p:false,d:,l:100 ms");
 }
 
 }  // namespace webrtc