Allow extra chars for definition intent selection.

Also changed to check the threshold with character size instead of byte
size.

Bug: b/160639930
Test: unit tests
Change-Id: I0cefba23ef46ce7bda7ccb57adf3c46481f0d389
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2285509Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Li Lin <llin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#786340}

chromeos/components/quick_answers/understanding/intent_generator.cc

@@ -27,7 +27,7 @@ using machine_learning::mojom::TextClassifier;
 // TODO(llin): Finalize on the threshold based on user feedback.
 constexpr int kUnitConversionIntentAndSelectionLengthDiffThreshold = 5;
 constexpr int kTranslationTextLengthThreshold = 50;
-constexpr int kDefinitionIntentAndSelectionLengthDiffThreshold = 0;
+constexpr int kDefinitionIntentAndSelectionLengthDiffThreshold = 2;
 
 const std::map<std::string, IntentType>& GetIntentTypeMap() {
   static base::NoDestructor<std::map<std::string, IntentType>> kIntentTypeMap(
@@ -65,8 +65,8 @@ IntentType RewriteIntent(const std::string& selected_text,
                          const std::string& entity_str,
                          const IntentType intent) {
   int intent_and_selection_length_diff =
-      selected_text.length() - entity_str.length();
-
+      base::UTF8ToUTF16(selected_text).length() -
+      base::UTF8ToUTF16(entity_str).length();
   if ((intent == IntentType::kUnit &&
        intent_and_selection_length_diff >
            kUnitConversionIntentAndSelectionLengthDiffThreshold) ||

chromeos/components/quick_answers/understanding/intent_generator_unittest.cc

@@ -203,7 +203,38 @@ TEST_F(IntentGeneratorTest, TextAnnotationDefinitionIntent) {
   EXPECT_EQ("unfathomable", intent_text_);
 }
 
-TEST_F(IntentGeneratorTest, TextAnnotationDefinitionIntentExtraChars) {
+TEST_F(IntentGeneratorTest,
+       TextAnnotationDefinitionIntentExtraCharsBelowThreshold) {
+  std::unique_ptr<QuickAnswersRequest> quick_answers_request =
+      std::make_unique<QuickAnswersRequest>();
+  quick_answers_request->selected_text = "“unfathomable”";
+
+  // Create the test annotations.
+  std::vector<TextEntityPtr> entities;
+  entities.emplace_back(
+      TextEntity::New("dictionary",             // Entity name.
+                      1.0,                      // Confidence score.
+                      TextEntityData::New()));  // Data extracted.
+
+  auto dictionary_annotation = TextAnnotation::New(1,   // Start offset.
+                                                   13,  // End offset.
+                                                   std::move(entities));
+
+  std::vector<TextAnnotationPtr> annotations;
+  annotations.push_back(dictionary_annotation->Clone());
+
+  UseFakeServiceConnection(annotations);
+
+  intent_generator_->GenerateIntent(*quick_answers_request);
+
+  task_environment_.RunUntilIdle();
+
+  EXPECT_EQ(IntentType::kDictionary, intent_type_);
+  EXPECT_EQ("unfathomable", intent_text_);
+}
+
+TEST_F(IntentGeneratorTest,
+       TextAnnotationDefinitionIntentExtraCharsAboveThreshold) {
   std::unique_ptr<QuickAnswersRequest> quick_answers_request =
       std::make_unique<QuickAnswersRequest>();
   quick_answers_request->selected_text = "the unfathomable";