Fix exact system language to tts language matching

Bug: 896910
Change-Id: I7b8b08147943a214900e6b835ce7c45016167b22
Reviewed-on: https://chromium-review.googlesource.com/c/1292151
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Katie Dektar <katie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601393}

chrome/browser/speech/tts_controller_impl.cc

@@ -501,20 +501,13 @@ int TtsControllerImpl::GetMatchingVoice(
     if (!voice.lang.empty() && !utterance->lang().empty()) {
       // An exact language match is worth more than a partial match.
       if (voice.lang == utterance->lang()) {
-        score += 64;
+        score += 128;
       } else if (l10n_util::GetLanguage(voice.lang) ==
                  l10n_util::GetLanguage(utterance->lang())) {
-        score += 32;
+        score += 64;
       }
     }
 
-    // Prefer the system language after that.
-    if (!voice.lang.empty()) {
-      if (l10n_util::GetLanguage(voice.lang) ==
-          l10n_util::GetLanguage(app_lang))
-        score += 16;
-    }
-
     // Next, prefer required event types.
     if (utterance->required_event_types().size() > 0) {
       bool has_all_required_event_types = true;
@@ -526,11 +519,11 @@ int TtsControllerImpl::GetMatchingVoice(
         }
       }
       if (has_all_required_event_types)
-        score += 8;
+        score += 32;
     }
 
 #if defined(OS_CHROMEOS)
-    // Finally, prefer the user's preference voice for the language:
+    // Prefer the user's preference voice for the language:
     if (lang_to_voice_pref) {
       // First prefer the user's preference voice for the utterance language,
       // if the utterance language is specified.
@@ -539,7 +532,7 @@ int TtsControllerImpl::GetMatchingVoice(
         lang_to_voice_pref->GetString(l10n_util::GetLanguage(utterance->lang()),
                                       &voice_id);
         if (VoiceIdMatches(voice_id, voice))
-          score += 4;
+          score += 16;
       }
 
       // Then prefer the user's preference voice for the system language.
@@ -548,7 +541,7 @@ int TtsControllerImpl::GetMatchingVoice(
       lang_to_voice_pref->GetString(l10n_util::GetLanguage(app_lang),
                                     &voice_id);
       if (VoiceIdMatches(voice_id, voice))
-        score += 2;
+        score += 8;
 
       // Finally, prefer the user's preference voice for any language. This will
       // pick the default voice if there is no better match for the current
@@ -556,10 +549,20 @@ int TtsControllerImpl::GetMatchingVoice(
       voice_id.clear();
       lang_to_voice_pref->GetString("noLanguageCode", &voice_id);
       if (VoiceIdMatches(voice_id, voice))
-        score += 1;
+        score += 4;
     }
 #endif  // defined(OS_CHROMEOS)
 
+    // Finally, prefer system language.
+    if (!voice.lang.empty()) {
+      if (voice.lang == app_lang) {
+        score += 2;
+      } else if (l10n_util::GetLanguage(voice.lang) ==
+                 l10n_util::GetLanguage(app_lang)) {
+        score += 1;
+      }
+    }
+
     if (score > best_score) {
       best_score = score;
       best_score_index = i;

chrome/browser/speech/tts_controller_unittest.cc

@@ -5,6 +5,7 @@
 // Unit tests for the TTS Controller.
 
 #include "base/values.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/speech/tts_controller_impl.h"
 #include "chrome/browser/speech/tts_platform.h"
 #include "chrome/common/pref_names.h"
@@ -80,7 +81,7 @@ TEST_F(TtsControllerTest, TestGetMatchingVoice) {
       std::make_unique<TestableTtsController>();
 #if defined(OS_CHROMEOS)
   TestingPrefServiceSimple pref_service_;
-  // Uses default pref voices
+  // Uses default pref voices.
   std::unique_ptr<base::DictionaryValue> lang_to_voices =
       std::make_unique<base::DictionaryValue>();
   lang_to_voices->SetKey(
@@ -202,6 +203,47 @@ TEST_F(TtsControllerTest, TestGetMatchingVoice) {
     utterance.set_extension_id("");
     utterance.set_lang("");
     EXPECT_EQ(8, tts_controller->GetMatchingVoice(&utterance, voices));
+#endif  // defined(OS_CHROMEOS)
+  }
+
+  {
+    // Check voices against system language.
+    std::vector<VoiceData> voices;
+    VoiceData voice0;
+    voice0.extension_id = "id0";
+    voice0.name = "voice0";
+    voice0.lang = "en-GB";
+    voices.push_back(voice0);
+    VoiceData voice1;
+    voice1.extension_id = "id1";
+    voice1.name = "voice1";
+    voice1.lang = "en-US";
+    voices.push_back(voice1);
+    Utterance utterance(nullptr);
+
+    // voice1 is matched against the exact default system language.
+    g_browser_process->SetApplicationLocale("en-US", "en-US");
+    utterance.set_lang("");
+    EXPECT_EQ(1, tts_controller->GetMatchingVoice(&utterance, voices));
+
+    // voice0 is matched against the system language which has no region piece.
+    g_browser_process->SetApplicationLocale("en", "en");
+    utterance.set_lang("");
+    EXPECT_EQ(0, tts_controller->GetMatchingVoice(&utterance, voices));
+
+#if defined(OS_CHROMEOS)
+    // Add another preference.
+    std::unique_ptr<base::DictionaryValue> lang_to_voices =
+        std::make_unique<base::DictionaryValue>();
+    lang_to_voices->SetKey(
+        "en", base::Value("{\"name\":\"voice0\",\"extension\":\"id0\"}"));
+
+    pref_service_.SetUserPref(prefs::kTextToSpeechLangToVoiceName,
+                              std::move(lang_to_voices));
+
+    // voice0 is matched against the pref over the system language.
+    g_browser_process->SetApplicationLocale("en-US", "en-US");
+    EXPECT_EQ(0, tts_controller->GetMatchingVoice(&utterance, voices));
 #endif  // defined(OS_CHROMEOS)
   }
 }