[TTS][Template URL] Add fluent languages support.

Adds support for a new Contextual Search Resolve-request parameter
to provide a list of fluent languages.  The server can use these
as additional hints from the Chrome Language Model for the
user's preferred languages to translate into.

BUG= 1084600, 1093833, 1095090

Change-Id: Ieece911ca84854effcd830f4d0d7ec64e088f700
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2261422
Commit-Queue: Donn Denman <donnd@chromium.org>
Reviewed-by: manuk hovanesian <manukh@chromium.org>
Auto-Submit: Donn Denman <donnd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781650}

chrome/browser/android/contextualsearch/contextual_search_delegate.cc

@@ -308,7 +308,7 @@ std::string ContextualSearchDelegate::BuildRequestUrl(
       context->GetPreviousEventId(), context->GetPreviousEventResults(),
       context->GetExactResolve(),
       context->GetTranslationLanguages().detected_language,
-      context->GetTranslationLanguages().target_language);
+      context->GetTranslationLanguages().target_language, std::string());
 
   search_terms_args.contextual_search_params = params;
 

components/search_engines/template_url.cc

@@ -227,7 +227,8 @@ TemplateURLRef::SearchTermsArgs::ContextualSearchParams::ContextualSearchParams(
     int previous_event_results,
     bool is_exact_search,
     std::string source_lang,
-    std::string target_lang)
+    std::string target_lang,
+    std::string fluent_languages)
     : version(version),
       contextual_cards_version(contextual_cards_version),
       home_country(home_country),
@@ -235,7 +236,8 @@ TemplateURLRef::SearchTermsArgs::ContextualSearchParams::ContextualSearchParams(
       previous_event_results(previous_event_results),
       is_exact_search(is_exact_search),
       source_lang(source_lang),
-      target_lang(target_lang) {}
+      target_lang(target_lang),
+      fluent_languages(fluent_languages) {}
 
 TemplateURLRef::SearchTermsArgs::ContextualSearchParams::ContextualSearchParams(
     const ContextualSearchParams& other) = default;
@@ -1004,6 +1006,8 @@ std::string TemplateURLRef::HandleReplacements(
           args.push_back("tlitesl=" + params.source_lang);
         if (!params.target_lang.empty())
           args.push_back("tlitetl=" + params.target_lang);
+        if (!params.fluent_languages.empty())
+          args.push_back("ctxs_fls=" + params.fluent_languages);
 
         HandleReplacement(std::string(), base::JoinString(args, "&"), *i, &url);
         break;

components/search_engines/template_url.h

@@ -118,6 +118,10 @@ class TemplateURLRef {
       // The |target_lang| specifies the best language to translate into for
       // the user, which also indicates when translation is appropriate or
       // helpful.  This comes from the Chrome Language Model.
+      // The |fluent_languages| string specifies the languages the user
+      // is fluent in reading.  This acts as an alternate set of languages
+      // to consider translating into.  The languages are ordered by
+      // fluency, and encoded as a comma-separated list of BCP 47 languages.
       ContextualSearchParams(int version,
                              int contextual_cards_version,
                              std::string home_country,
@@ -125,7 +129,8 @@ class TemplateURLRef {
                              int previous_event_results,
                              bool is_exact_search,
                              std::string source_lang,
-                             std::string target_lang);
+                             std::string target_lang,
+                             std::string fluent_languages);
       ContextualSearchParams(const ContextualSearchParams& other);
       ~ContextualSearchParams();
 
@@ -162,6 +167,10 @@ class TemplateURLRef {
 
       // Target language string to be translated into.
       std::string target_lang;
+
+      // Alternate target languages that the user is fluent in, encoded in a
+      // single string.
+      std::string fluent_languages;
     };
 
     // Estimates dynamic memory usage.

components/search_engines/template_url_unittest.cc

@@ -1741,7 +1741,8 @@ TEST_F(TemplateURLTest, ContextualSearchParameters) {
   // Test the current common case, which uses no home country or previous
   // event.
   TemplateURLRef::SearchTermsArgs::ContextualSearchParams params(
-      2, 1, std::string(), 0, 0, false, std::string(), std::string());
+      2, 1, std::string(), 0, 0, false, std::string(), std::string(),
+      std::string());
   search_terms_args.contextual_search_params = params;
   result = url.url_ref().ReplaceSearchTerms(search_terms_args,
                                             search_terms_data_);
@@ -1754,7 +1755,8 @@ TEST_F(TemplateURLTest, ContextualSearchParameters) {
   // Test the home country and non-zero event data case.
   search_terms_args.contextual_search_params =
       TemplateURLRef::SearchTermsArgs::ContextualSearchParams(
-          2, 2, "CH", 1657713458, 5, false, std::string(), std::string());
+          2, 2, "CH", 1657713458, 5, false, std::string(), std::string(),
+          std::string());
   result =
       url.url_ref().ReplaceSearchTerms(search_terms_args, search_terms_data_);
 
@@ -1770,7 +1772,8 @@ TEST_F(TemplateURLTest, ContextualSearchParameters) {
   // Test exact-search.
   search_terms_args.contextual_search_params =
       TemplateURLRef::SearchTermsArgs::ContextualSearchParams(
-          2, 1, std::string(), 0, 0, true, std::string(), std::string());
+          2, 1, std::string(), 0, 0, true, std::string(), std::string(),
+          std::string());
   result =
       url.url_ref().ReplaceSearchTerms(search_terms_args, search_terms_data_);
   // Find our param.
@@ -1780,7 +1783,7 @@ TEST_F(TemplateURLTest, ContextualSearchParameters) {
   // Test source and target languages.
   search_terms_args.contextual_search_params =
       TemplateURLRef::SearchTermsArgs::ContextualSearchParams(
-          2, 1, std::string(), 0, 0, true, "es", "de");
+          2, 1, std::string(), 0, 0, true, "es", "de", std::string());
   result =
       url.url_ref().ReplaceSearchTerms(search_terms_args, search_terms_data_);
   // Find our params.
@@ -1788,6 +1791,17 @@ TEST_F(TemplateURLTest, ContextualSearchParameters) {
   EXPECT_NE(source_pos, std::string::npos);
   size_t target_pos = result.find("tlitetl=de");
   EXPECT_NE(target_pos, std::string::npos);
+
+  // Test fluent languages.
+  search_terms_args.contextual_search_params =
+      TemplateURLRef::SearchTermsArgs::ContextualSearchParams(
+          2, 1, std::string(), 0, 0, true, std::string(), std::string(),
+          "es,de");
+  result =
+      url.url_ref().ReplaceSearchTerms(search_terms_args, search_terms_data_);
+  // Find our param.  These may actually be URL encoded.
+  size_t fluent_pos = result.find("&ctxs_fls=es,de");
+  EXPECT_NE(fluent_pos, std::string::npos);
 }
 
 TEST_F(TemplateURLTest, GenerateKeyword) {