Removed migration flags for typing corrections.

These flags were introduced to make trivial modifications on the scoring functions.

Confirmed that these migration has no quality impact through 10% rollout experiment.

PiperOrigin-RevId: 681765823

src/prediction/dictionary_predictor.cc

@@ -510,13 +510,10 @@ void DictionaryPredictor::MaybeSuppressAggressiveTypingCorrection(
   // Top is already literal.
   const auto &top_result = results->front();
 
-  const auto &params = request.request().decoder_experiment_params();
-
   auto is_typing_correction = [&](const Result &result) {
-    return (result.types & PredictionType::TYPING_CORRECTION ||
-            (params.fix_legacy_typing_correction_behavior() &&
-             (result.candidate_attributes &
-              Segment::Candidate::TYPING_CORRECTION)));
+    return (
+        result.types & PredictionType::TYPING_CORRECTION ||
+        (result.candidate_attributes & Segment::Candidate::TYPING_CORRECTION));
   };
 
   if (!is_typing_correction(*top_result)) {

src/prediction/dictionary_predictor_test.cc

@@ -1764,14 +1764,11 @@ TEST_F(DictionaryPredictorTest, MaybeSuppressAggressiveTypingCorrectionTest) {
   EXPECT_EQ(get_top_value(), "value_0");     // top is typing correction.
   EXPECT_EQ(get_second_value(), "value_3");  // second is literal.
 
-  // Tests fix_legacy_typing_correction_behavior
   reset_results_ptrs();
   params.literal_on_top = true;
   params.literal_at_least_second = false;
   results[3].candidate_attributes = Segment::Candidate::TYPING_CORRECTION;
 
-  request_->mutable_decoder_experiment_params()
-      ->set_fix_legacy_typing_correction_behavior(true);
   DictionaryPredictorTestPeer::MaybeSuppressAggressiveTypingCorrection(
       *convreq_for_suggestion_, params, &results_ptrs);
   EXPECT_EQ(get_top_value(), "value_4");

src/protocol/commands.proto

@@ -659,9 +659,6 @@ message DecoderExperimentParams {
   // <= katakana_override_min_per_char_cost
   optional int32 katakana_override_min_per_char_cost = 91 [default = 0];
 
-  // Treats the legacy typing correction candidate as
-  // literal-on-top or literal-at-least-second.
-  optional bool fix_legacy_typing_correction_behavior = 92 [default = false];
 }
 
 // Clients' request to the server.