Adding fluent language model to iOS.

Change-Id: Ie542c2ea632f7bddf50914f7af611bb5911ca427
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1798823Reviewed-by: Alexandre Frechette <frechette@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Alexandre Frechette <frechette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#698484}

ios/chrome/browser/language/language_model_manager_factory.cc

@@ -8,6 +8,7 @@
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "components/language/core/browser/baseline_language_model.h"
+#include "components/language/core/browser/fluent_language_model.h"
 #include "components/language/core/browser/heuristic_language_model.h"
 #include "components/language/core/browser/language_model.h"
 #include "components/language/core/browser/language_model_manager.h"
@@ -26,6 +27,14 @@ void PrepareLanguageModels(ios::ChromeBrowserState* const chrome_state,
   // Create and set the primary Language Model to use based on the state of
   // experiments.
   switch (language::GetOverrideLanguageModel()) {
+    case language::OverrideLanguageModel::FLUENT:
+      manager->AddModel(
+          language::LanguageModelManager::ModelType::FLUENT,
+          std::make_unique<language::FluentLanguageModel>(
+              chrome_state->GetPrefs(), language::prefs::kAcceptLanguages));
+      manager->SetPrimaryModel(
+          language::LanguageModelManager::ModelType::FLUENT);
+      break;
     case language::OverrideLanguageModel::HEURISTIC:
       manager->AddModel(language::LanguageModelManager::ModelType::HEURISTIC,
                         std::make_unique<language::HeuristicLanguageModel>(

ios/web_view/internal/language/web_view_language_model_manager_factory.mm

@@ -9,6 +9,7 @@
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "components/language/core/browser/baseline_language_model.h"
+#include "components/language/core/browser/fluent_language_model.h"
 #include "components/language/core/browser/heuristic_language_model.h"
 #include "components/language/core/browser/language_model.h"
 #include "components/language/core/browser/language_model_manager.h"
@@ -42,6 +43,14 @@ void PrepareLanguageModels(WebViewBrowserState* const web_view_browser_state,
       manager->SetPrimaryModel(
           language::LanguageModelManager::ModelType::HEURISTIC);
       break;
+    case language::OverrideLanguageModel::FLUENT:
+      manager->AddModel(language::LanguageModelManager::ModelType::FLUENT,
+                        std::make_unique<language::FluentLanguageModel>(
+                            web_view_browser_state->GetPrefs(),
+                            language::prefs::kAcceptLanguages));
+      manager->SetPrimaryModel(
+          language::LanguageModelManager::ModelType::FLUENT);
+      break;
     case language::OverrideLanguageModel::DEFAULT:
     default:
       manager->AddModel(

testing/variations/fieldtrial_testing_config.json

@@ -6343,6 +6343,21 @@
             ]
         }
     ],
+    "UseFluentLanguageModel": [
+        {
+            "platforms": [
+                "ios"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "UseFluentLanguageModel"
+                    ]
+                }
+            ]
+        }
+    ],
     "UsePdfCompositorServiceForPrint": [
         {
             "platforms": [