Moved language detection dispatch into the language component on iOS.

This comprises:
  - Attaching an iOS language detection client (similar to the
    existing Content-based client) to each web state
  - Updating the language detection controller (which does the actual
    CLD) to notify the language detection client rather than translate
    code, and to use core datatypes (rather than iOS-specific ones)
  - Updating the translate driver to receive language info via a
    callback from the language detection client
  - Updating unit and integration tests to account for these changes

Bug: 755856
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I7544863835d0d507a3e1453973f55c7fc918ba83
Reviewed-on: https://chromium-review.googlesource.com/740421
Commit-Queue: Michael Martis <martis@chromium.org>
Reviewed-by: Renjie Liu <renjieliu@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513070}

components/language/ios/browser/BUILD.gn

+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("browser") {
+  configs += [ "//build/config/compiler:enable_arc" ]
+  sources = [
+    "ios_language_detection_tab_helper.h",
+    "ios_language_detection_tab_helper.mm",
+  ]
+
+  deps = [
+    "//base",
+    "//components/language/core/browser",
+    "//components/translate/core/common",
+    "//ios/web",
+    "//net",
+  ]
+}

components/language/ios/browser/DEPS

+include_rules = [
+  "+components/translate/core/common",
+]

components/language/ios/browser/ios_language_detection_tab_helper.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_LANUGUAGE_IOS_BROWSER_IOS_LANGUAGE_DETECTION_TAB_HELPER_H_
+#define COMPONENTS_LANUGUAGE_IOS_BROWSER_IOS_LANGUAGE_DETECTION_TAB_HELPER_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "ios/web/public/web_state/web_state_user_data.h"
+
+namespace translate {
+struct LanguageDetectionDetails;
+}  // namespace translate
+
+namespace language {
+
+class UrlLanguageHistogram;
+
+// Dispatches language detection messages to language and translate components.
+class IOSLanguageDetectionTabHelper
+    : public web::WebStateUserData<IOSLanguageDetectionTabHelper> {
+ public:
+  using Callback =
+      base::RepeatingCallback<void(const translate::LanguageDetectionDetails&)>;
+
+  ~IOSLanguageDetectionTabHelper() override;
+
+  // Attach a new helper to the given WebState. We cannot use the implementation
+  // from WebStateUserData as we are injecting the histogram and translate
+  // callback differently on iOS and iOS WebView.
+  static void CreateForWebState(web::WebState* web_state,
+                                const Callback& translate_callback,
+                                UrlLanguageHistogram* url_language_histogram);
+
+  // Called on page language detection.
+  void OnLanguageDetermined(const translate::LanguageDetectionDetails& details);
+
+  // Add an extra listener for language detection. May only be used in tests.
+  void SetExtraCallbackForTesting(const Callback& callback);
+
+ private:
+  IOSLanguageDetectionTabHelper(
+      const Callback& translate_callback,
+      UrlLanguageHistogram* const url_language_histogram);
+  friend class web::WebStateUserData<IOSLanguageDetectionTabHelper>;
+
+  const Callback translate_callback_;
+  UrlLanguageHistogram* const url_language_histogram_;
+
+  Callback extra_callback_for_testing_;
+
+  DISALLOW_COPY_AND_ASSIGN(IOSLanguageDetectionTabHelper);
+};
+
+}  // namespace language
+
+#endif  // COMPONENTS_LANUGUAGE_IOS_BROWSER_IOS_LANGUAGE_DETECTION_TAB_HELPER_H_

components/language/ios/browser/ios_language_detection_tab_helper.mm

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/language/ios/browser/ios_language_detection_tab_helper.h"
+
+#include "components/language/core/browser/url_language_histogram.h"
+#include "components/translate/core/common/language_detection_details.h"
+
+DEFINE_WEB_STATE_USER_DATA_KEY(language::IOSLanguageDetectionTabHelper);
+
+namespace language {
+
+IOSLanguageDetectionTabHelper::IOSLanguageDetectionTabHelper(
+    const Callback& translate_callback,
+    UrlLanguageHistogram* const url_language_histogram)
+    : translate_callback_(translate_callback),
+      url_language_histogram_(url_language_histogram) {}
+
+IOSLanguageDetectionTabHelper::~IOSLanguageDetectionTabHelper() = default;
+
+// static
+void IOSLanguageDetectionTabHelper::CreateForWebState(
+    web::WebState* web_state,
+    const Callback& translate_callback,
+    UrlLanguageHistogram* const url_language_histogram) {
+  DCHECK(web_state);
+  if (!FromWebState(web_state)) {
+    web_state->SetUserData(UserDataKey(),
+                           base::WrapUnique(new IOSLanguageDetectionTabHelper(
+                               translate_callback, url_language_histogram)));
+  }
+}
+
+void IOSLanguageDetectionTabHelper::OnLanguageDetermined(
+    const translate::LanguageDetectionDetails& details) {
+  // Update language histogram.
+  if (url_language_histogram_ && details.is_cld_reliable) {
+    url_language_histogram_->OnPageVisited(details.cld_language);
+  }
+
+  // Update translate.
+  translate_callback_.Run(details);
+
+  // Optionally update testing callback.
+  if (extra_callback_for_testing_) {
+    extra_callback_for_testing_.Run(details);
+  }
+}
+
+void IOSLanguageDetectionTabHelper::SetExtraCallbackForTesting(
+    const Callback& callback) {
+  extra_callback_for_testing_ = callback;
+}
+
+}  // namespace language

components/translate/ios/browser/BUILD.gn

@@ -24,7 +24,7 @@ source_set("browser") {
   deps = [
     ":injected_js",
     "//base",
-    "//components/language/core/browser",
+    "//components/language/ios/browser",
     "//components/prefs",
     "//components/translate/core/browser",
     "//components/translate/core/common",
@@ -56,9 +56,11 @@ source_set("unit_tests") {
   deps = [
     ":browser",
     "//base",
+    "//components/language/ios/browser",
     "//components/prefs:test_support",
     "//components/resources",
     "//components/translate/core/browser",
+    "//components/translate/core/common",
     "//ios/web/public/test",
     "//ios/web/public/test/fakes",
     "//net:net",

components/translate/ios/browser/ios_translate_driver.h

@@ -10,6 +10,7 @@
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "components/language/ios/browser/ios_language_detection_tab_helper.h"
 #include "components/translate/core/browser/translate_driver.h"
 #include "components/translate/ios/browser/language_detection_controller.h"
 #include "components/translate/ios/browser/translate_controller.h"
@@ -17,10 +18,6 @@
 
 @class CRWJSInjectionReceiver;
 
-namespace language {
-class UrlLanguageHistogram;
-}
-
 namespace web {
 class NavigationManager;
 class WebState;
@@ -37,8 +34,7 @@ class IOSTranslateDriver : public TranslateDriver,
  public:
   IOSTranslateDriver(web::WebState* web_state,
                      web::NavigationManager* navigation_manager,
-                     TranslateManager* translate_manager,
-                     language::UrlLanguageHistogram* language_histogram);
+                     TranslateManager* translate_manager);
   ~IOSTranslateDriver() override;
 
   LanguageDetectionController* language_detection_controller() {
@@ -49,6 +45,10 @@ class IOSTranslateDriver : public TranslateDriver,
     return translate_controller_.get();
   }
 
+  // Creates a callback to be used when language detection occurs.
+  language::IOSLanguageDetectionTabHelper::Callback
+  CreateLanguageDetectionCallback();
+
   // web::WebStateObserver methods.
   void NavigationItemCommitted(
       web::WebState* web_state,
@@ -89,9 +89,8 @@ class IOSTranslateDriver : public TranslateDriver,
   // being destroyed.
   bool IsPageValid(int page_seq_no) const;
 
-  // Callback for LanguageDetectionController.
-  void OnLanguageDetermined(
-      const LanguageDetectionController::DetectionDetails& details);
+  // Used to kick off translation process.
+  void OnLanguageDetermined(const LanguageDetectionDetails& details);
 
   // TranslateController::Observer methods.
   void OnTranslateScriptReady(bool success,
@@ -104,14 +103,9 @@ class IOSTranslateDriver : public TranslateDriver,
   // The navigation manager of the tab we are associated with.
   web::NavigationManager* navigation_manager_;
 
-  // Model to be notified about detected language of every page visited.
-  language::UrlLanguageHistogram* language_histogram_;
-
   base::WeakPtr<TranslateManager> translate_manager_;
   std::unique_ptr<TranslateController> translate_controller_;
   std::unique_ptr<LanguageDetectionController> language_detection_controller_;
-  std::unique_ptr<LanguageDetectionController::CallbackList::Subscription>
-      language_detection_callback_subscription_;
 
   // An ever-increasing sequence number of the current page, used to match up
   // translation requests with responses.

components/translate/ios/browser/ios_translate_driver.mm

@@ -9,7 +9,6 @@
 #include "base/strings/sys_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
-#include "components/language/core/browser/url_language_histogram.h"
 #include "components/translate/core/browser/translate_client.h"
 #include "components/translate/core/browser/translate_manager.h"
 #include "components/translate/core/common/language_detection_details.h"
@@ -51,11 +50,9 @@ const char kAutoDetectionLanguage[] = "auto";
 IOSTranslateDriver::IOSTranslateDriver(
     web::WebState* web_state,
     web::NavigationManager* navigation_manager,
-    TranslateManager* translate_manager,
-    language::UrlLanguageHistogram* language_histogram)
+    TranslateManager* translate_manager)
     : web::WebStateObserver(web_state),
       navigation_manager_(navigation_manager),
-      language_histogram_(language_histogram),
       translate_manager_(translate_manager->GetWeakPtr()),
       page_seq_no_(0),
       pending_page_seq_no_(0),
@@ -74,10 +71,7 @@ IOSTranslateDriver::IOSTranslateDriver(
   language_detection_controller_.reset(new LanguageDetectionController(
       web_state, language_detection_manager,
       translate_manager_->translate_client()->GetPrefs()));
-  language_detection_callback_subscription_ =
-      language_detection_controller_->RegisterLanguageDetectionCallback(
-          base::Bind(&IOSTranslateDriver::OnLanguageDetermined,
-                     base::Unretained(this)));
+
   // Create the translate controller.
   JsTranslateManager* js_translate_manager = static_cast<JsTranslateManager*>(
       [receiver instanceOfClass:[JsTranslateManager class]]);
@@ -89,24 +83,20 @@ IOSTranslateDriver::IOSTranslateDriver(
 IOSTranslateDriver::~IOSTranslateDriver() {
 }
 
+language::IOSLanguageDetectionTabHelper::Callback
+IOSTranslateDriver::CreateLanguageDetectionCallback() {
+  return base::Bind(&IOSTranslateDriver::OnLanguageDetermined,
+                    weak_method_factory_.GetWeakPtr());
+}
+
 void IOSTranslateDriver::OnLanguageDetermined(
-    const LanguageDetectionController::DetectionDetails& details) {
+    const translate::LanguageDetectionDetails& details) {
   if (!translate_manager_)
     return;
   translate_manager_->GetLanguageState().LanguageDetermined(
       details.adopted_language, true);
 
-  // Update language histogram.
-  if (language_histogram_ && details.is_cld_reliable) {
-    language_histogram_->OnPageVisited(details.cld_language);
-  }
-
-  translate::LanguageDetectionDetails detection_details;
-  detection_details.cld_language = details.cld_language;
-  detection_details.is_cld_reliable = details.is_cld_reliable;
-  detection_details.adopted_language = details.adopted_language;
-  translate_manager_->translate_client()->RecordLanguageDetectionEvent(
-      detection_details);
+  translate_manager_->translate_client()->RecordLanguageDetectionEvent(details);
 
   if (web_state())
     translate_manager_->InitiateTranslation(details.adopted_language);

components/translate/ios/browser/language_detection_controller.h

@@ -37,44 +37,11 @@ namespace translate {
 
 class LanguageDetectionController : public web::WebStateObserver {
  public:
-  // Language detection details, passed to language detection callbacks.
-  // TODO(crbug.com/715447): Investigate if we can use the existing
-  // detection_details under
-  // components/translate/core/common/language_detection_details.h.
-  struct DetectionDetails {
-    DetectionDetails();
-    DetectionDetails(const DetectionDetails& other);
-    ~DetectionDetails();
-
-    // The language detected by the content (Content-Language).
-    std::string content_language;
-
-    // The language written in the lang attribute of the html element.
-    std::string html_root_language;
-
-    // The adopted language.
-    std::string adopted_language;
-
-    // The language detected by CLD.
-    std::string cld_language;
-
-    // Whether the CLD detection is reliable or not.
-    bool is_cld_reliable;
-  };
-
   LanguageDetectionController(web::WebState* web_state,
                               JsLanguageDetectionManager* manager,
                               PrefService* prefs);
   ~LanguageDetectionController() override;
 
-  // Callback types for language detection events.
-  typedef base::Callback<void(const DetectionDetails&)> Callback;
-  typedef base::CallbackList<void(const DetectionDetails&)> CallbackList;
-
-  // Registers a callback for language detection events.
-  std::unique_ptr<CallbackList::Subscription> RegisterLanguageDetectionCallback(
-      const Callback& callback);
-
  private:
   FRIEND_TEST_ALL_PREFIXES(LanguageDetectionControllerTest, OnTextCaptured);
   FRIEND_TEST_ALL_PREFIXES(LanguageDetectionControllerTest,
@@ -93,6 +60,7 @@ class LanguageDetectionController : public web::WebStateObserver {
   // JsLanguageDetectionManager.
   void OnTextRetrieved(const std::string& http_content_language,
                        const std::string& html_lang,
+                       const GURL& url,
                        const base::string16& text);
 
   // Extracts "content-language" header into content_language_header_ variable.
@@ -106,7 +74,6 @@ class LanguageDetectionController : public web::WebStateObserver {
                            web::NavigationContext* navigation_context) override;
   void WebStateDestroyed(web::WebState* web_state) override;
 
-  CallbackList language_detection_callbacks_;
   JsLanguageDetectionManager* js_manager_;
   BooleanPrefMember translate_enabled_;
   std::string content_language_header_;

components/translate/ios/browser/language_detection_controller.mm

@@ -10,8 +10,10 @@
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
+#include "components/language/ios/browser/ios_language_detection_tab_helper.h"
 #include "components/prefs/pref_member.h"
 #include "components/translate/core/browser/translate_pref_names.h"
+#include "components/translate/core/common/language_detection_details.h"
 #include "components/translate/core/language_detection/language_detection_util.h"
 #import "components/translate/ios/browser/js_language_detection_manager.h"
 #include "components/translate/ios/browser/string_clipping_util.h"
@@ -53,20 +55,6 @@ LanguageDetectionController::LanguageDetectionController(
 LanguageDetectionController::~LanguageDetectionController() {
 }
 
-LanguageDetectionController::DetectionDetails::DetectionDetails()
-    : is_cld_reliable(false) {}
-
-LanguageDetectionController::DetectionDetails::DetectionDetails(
-    const DetectionDetails& other) = default;
-
-LanguageDetectionController::DetectionDetails::~DetectionDetails() = default;
-
-std::unique_ptr<LanguageDetectionController::CallbackList::Subscription>
-LanguageDetectionController::RegisterLanguageDetectionCallback(
-    const Callback& callback) {
-  return language_detection_callbacks_.Add(callback);
-}
-
 void LanguageDetectionController::StartLanguageDetection() {
   if (!translate_enabled_.GetValue())
     return;  // Translate disabled in preferences.
@@ -116,13 +104,14 @@ bool LanguageDetectionController::OnTextCaptured(
   [js_manager_ retrieveBufferedTextContent:
                    base::Bind(&LanguageDetectionController::OnTextRetrieved,
                               weak_method_factory_.GetWeakPtr(),
-                              http_content_language, html_lang)];
+                              http_content_language, html_lang, url)];
   return true;
 }
 
 void LanguageDetectionController::OnTextRetrieved(
     const std::string& http_content_language,
     const std::string& html_lang,
+    const GURL& url,
     const base::string16& text_content) {
   std::string cld_language;
   bool is_cld_reliable;
@@ -134,13 +123,20 @@ void LanguageDetectionController::OnTextRetrieved(
   if (language.empty())
     return;  // No language detected.
 
-  DetectionDetails details;
+  // Avoid an unnecessary copy of the full text content (which can be
+  // ~64kB) until we need it on iOS (e.g. for the translate internals
+  // page).
+  LanguageDetectionDetails details;
+  details.time = base::Time::Now();
+  details.url = url;
   details.content_language = http_content_language;
-  details.html_root_language = html_lang;
-  details.adopted_language = language;
   details.cld_language = cld_language;
   details.is_cld_reliable = is_cld_reliable;
-  language_detection_callbacks_.Notify(details);
+  details.html_root_language = html_lang;
+  details.adopted_language = language;
+
+  language::IOSLanguageDetectionTabHelper::FromWebState(web_state())
+      ->OnLanguageDetermined(details);
 }
 
 void LanguageDetectionController::ExtractContentLanguageHeader(

components/translate/ios/browser/language_detection_controller_unittest.mm

@@ -4,12 +4,15 @@
 
 #import "components/translate/ios/browser/language_detection_controller.h"
 
+#include "base/callback.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "components/language/ios/browser/ios_language_detection_tab_helper.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/testing_pref_service.h"
 #include "components/translate/core/browser/translate_pref_names.h"
+#include "components/translate/core/common/language_detection_details.h"
 #import "components/translate/ios/browser/js_language_detection_manager.h"
 #import "ios/web/public/test/fakes/fake_navigation_context.h"
 #import "ios/web/public/test/fakes/test_web_state.h"
@@ -37,22 +40,34 @@ namespace {
 
 class LanguageDetectionControllerTest : public PlatformTest {
  protected:
-  LanguageDetectionControllerTest() {
+  LanguageDetectionControllerTest() : details_(nullptr) {
     prefs_.registry()->RegisterBooleanPref(prefs::kEnableTranslate, true);
 
+    language::IOSLanguageDetectionTabHelper::CreateForWebState(
+        &web_state_,
+        base::Bind(&LanguageDetectionControllerTest::OnLanguageDetermined,
+                   base::Unretained(this)),
+        nullptr);
+
     MockJsLanguageDetectionManager* js_manager =
         [[MockJsLanguageDetectionManager alloc] init];
     controller_ = base::MakeUnique<LanguageDetectionController>(
         &web_state_, js_manager, &prefs_);
   }
 
-  LanguageDetectionController* controller() { return controller_.get(); }
   web::TestWebState& web_state() { return web_state_; }
+  LanguageDetectionController* controller() { return controller_.get(); }
+  LanguageDetectionDetails* details() { return details_.get(); }
 
  private:
   TestingPrefServiceSimple prefs_;
   web::TestWebState web_state_;
   std::unique_ptr<LanguageDetectionController> controller_;
+  std::unique_ptr<LanguageDetectionDetails> details_;
+
+  void OnLanguageDetermined(const LanguageDetectionDetails& details) {
+    details_ = base::MakeUnique<LanguageDetectionDetails>(details);
+  }
 };
 
 }  // namespace
@@ -64,17 +79,6 @@ TEST_F(LanguageDetectionControllerTest, OnTextCaptured) {
   const std::string kContentLanguage("fr");
   const std::string kUndefined("und");
 
-  __block bool block_was_called = false;
-  auto subscription =
-      controller()->RegisterLanguageDetectionCallback(base::BindBlockArc(
-          ^(const LanguageDetectionController::DetectionDetails& details) {
-            block_was_called = true;
-            EXPECT_EQ(kRootLanguage, details.html_root_language);
-            EXPECT_EQ(kContentLanguage, details.content_language);
-            EXPECT_FALSE(details.is_cld_reliable);
-            EXPECT_EQ(kUndefined, details.cld_language);
-          }));
-
   base::DictionaryValue command;
   command.SetString("command", "languageDetection.textCaptured");
   command.SetBoolean("translationAllowed", true);
@@ -83,7 +87,12 @@ TEST_F(LanguageDetectionControllerTest, OnTextCaptured) {
   command.SetString("httpContentLanguage", kContentLanguage);
   controller()->OnTextCaptured(command, GURL("http://google.com"), false);
 
-  EXPECT_TRUE(block_was_called);
+  const LanguageDetectionDetails* const details = this->details();
+  EXPECT_NE(nullptr, details);
+  EXPECT_EQ(kRootLanguage, details->html_root_language);
+  EXPECT_EQ(kContentLanguage, details->content_language);
+  EXPECT_FALSE(details->is_cld_reliable);
+  EXPECT_EQ(kUndefined, details->cld_language);
 }
 
 // Tests that Content-Language response header is used if httpContentLanguage
@@ -97,14 +106,6 @@ TEST_F(LanguageDetectionControllerTest, MissingHttpContentLanguage) {
   context.SetResponseHeaders(headers);
   web_state().OnNavigationFinished(&context);
 
-  __block bool block_was_called = false;
-  auto subscription =
-      controller()->RegisterLanguageDetectionCallback(base::BindBlockArc(
-          ^(const LanguageDetectionController::DetectionDetails& details) {
-            block_was_called = true;
-            EXPECT_EQ("fr", details.content_language);
-          }));
-
   base::DictionaryValue command;
   command.SetString("command", "languageDetection.textCaptured");
   command.SetBoolean("translationAllowed", true);
@@ -113,7 +114,9 @@ TEST_F(LanguageDetectionControllerTest, MissingHttpContentLanguage) {
   command.SetString("httpContentLanguage", "");
   controller()->OnTextCaptured(command, GURL("http://google.com"), false);
 
-  EXPECT_TRUE(block_was_called);
+  const LanguageDetectionDetails* const details = this->details();
+  EXPECT_NE(nullptr, details);
+  EXPECT_EQ("fr", details->content_language);
 }
 
 }  // namespace translate

ios/chrome/browser/tabs/BUILD.gn

@@ -72,6 +72,7 @@ source_set("tabs_internal") {
     "//components/history/ios/browser",
     "//components/infobars/core",
     "//components/keyed_service/core",
+    "//components/language/ios/browser",
     "//components/metrics_services_manager",
     "//components/navigation_metrics",
     "//components/prefs",
@@ -93,6 +94,7 @@ source_set("tabs_internal") {
     "//ios/chrome/browser/history",
     "//ios/chrome/browser/history:tab_helper",
     "//ios/chrome/browser/infobars",
+    "//ios/chrome/browser/language",
     "//ios/chrome/browser/metrics",
     "//ios/chrome/browser/metrics:metrics_internal",
     "//ios/chrome/browser/passwords",

ios/chrome/browser/tabs/tab_helper_util.mm

@@ -12,6 +12,7 @@
 #include "components/history/core/browser/top_sites.h"
 #import "components/history/ios/browser/web_state_top_sites_observer.h"
 #include "components/keyed_service/core/service_access_type.h"
+#import "components/language/ios/browser/ios_language_detection_tab_helper.h"
 #import "ios/chrome/browser/autofill/autofill_tab_helper.h"
 #import "ios/chrome/browser/autofill/form_input_accessory_view_tab_helper.h"
 #import "ios/chrome/browser/autofill/form_suggestion_tab_helper.h"
@@ -22,6 +23,7 @@
 #include "ios/chrome/browser/history/history_tab_helper.h"
 #include "ios/chrome/browser/history/top_sites_factory.h"
 #import "ios/chrome/browser/infobars/infobar_manager_impl.h"
+#import "ios/chrome/browser/language/url_language_histogram_factory.h"
 #import "ios/chrome/browser/passwords/password_tab_helper.h"
 #import "ios/chrome/browser/passwords/passwords_ui_delegate_impl.h"
 #include "ios/chrome/browser/reading_list/reading_list_model_factory.h"
@@ -80,7 +82,15 @@ void AttachTabHelpers(web::WebState* web_state) {
       ReadingListModelFactory::GetForBrowserState(browser_state);
   ReadingListWebStateObserver::FromWebState(web_state, model);
 
+  // The language detection helper accepts a callback from the translate
+  // client, so must be created after it.
   ChromeIOSTranslateClient::CreateForWebState(web_state);
+  language::IOSLanguageDetectionTabHelper::CreateForWebState(
+      web_state,
+      ChromeIOSTranslateClient::FromWebState(web_state)
+          ->GetTranslateDriver()
+          ->CreateLanguageDetectionCallback(),
+      UrlLanguageHistogramFactory::GetForBrowserState(browser_state));
 
   ios::ChromeBrowserState* original_browser_state =
       browser_state->GetOriginalChromeBrowserState();

ios/chrome/browser/translate/BUILD.gn

@@ -95,6 +95,7 @@ source_set("external_url_eg_tests") {
   deps = [
     ":translate",
     "//base",
+    "//components/language/ios/browser",
     "//components/strings",
     "//components/translate/core/browser",
     "//components/translate/core/common",

ios/chrome/browser/translate/chrome_ios_translate_client.h

@@ -49,7 +49,7 @@ class ChromeIOSTranslateClient
   translate::TranslateManager* GetTranslateManager();
 
   // TranslateClient implementation.
-  translate::TranslateDriver* GetTranslateDriver() override;
+  translate::IOSTranslateDriver* GetTranslateDriver() override;
   PrefService* GetPrefs() override;
   std::unique_ptr<translate::TranslatePrefs> GetTranslatePrefs() override;
   translate::TranslateAcceptLanguages* GetTranslateAcceptLanguages() override;

ios/chrome/browser/translate/chrome_ios_translate_client.mm

@@ -29,7 +29,6 @@
 #include "ios/chrome/browser/infobars/infobar_controller.h"
 #include "ios/chrome/browser/infobars/infobar_manager_impl.h"
 #include "ios/chrome/browser/language/language_model_factory.h"
-#include "ios/chrome/browser/language/url_language_histogram_factory.h"
 #include "ios/chrome/browser/pref_names.h"
 #import "ios/chrome/browser/sync/ios_user_event_service_factory.h"
 #import "ios/chrome/browser/translate/after_translate_infobar_controller.h"
@@ -65,10 +64,7 @@ ChromeIOSTranslateClient::ChromeIOSTranslateClient(web::WebState* web_state)
                   web_state->GetBrowserState())))),
       translate_driver_(web_state,
                         web_state->GetNavigationManager(),
-                        translate_manager_.get(),
-                        UrlLanguageHistogramFactory::GetForBrowserState(
-                            ios::ChromeBrowserState::FromBrowserState(
-                                web_state->GetBrowserState()))) {}
+                        translate_manager_.get()) {}
 
 ChromeIOSTranslateClient::~ChromeIOSTranslateClient() {
 }
@@ -163,7 +159,7 @@ void ChromeIOSTranslateClient::ShowTranslateUI(
       target_language, error_type, triggered_from_menu);
 }
 
-translate::TranslateDriver* ChromeIOSTranslateClient::GetTranslateDriver() {
+translate::IOSTranslateDriver* ChromeIOSTranslateClient::GetTranslateDriver() {
   return &translate_driver_;
 }
 

ios/chrome/browser/translate/translate_egtest.mm

@@ -10,10 +10,12 @@
 #include "base/strings/stringprintf.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
+#include "components/language/ios/browser/ios_language_detection_tab_helper.h"
 #include "components/strings/grit/components_strings.h"
 #include "components/translate/core/browser/translate_download_manager.h"
 #include "components/translate/core/browser/translate_manager.h"
 #include "components/translate/core/browser/translate_pref_names.h"
+#include "components/translate/core/common/language_detection_details.h"
 #include "components/translate/core/common/translate_constants.h"
 #include "components/translate/core/common/translate_switches.h"
 #include "components/translate/ios/browser/ios_translate_driver.h"
@@ -301,9 +303,7 @@ using translate::LanguageDetectionController;
 
 // Tests for translate.
 @interface TranslateTestCase : ChromeTestCase {
-  std::unique_ptr<LanguageDetectionController::CallbackList::Subscription>
-      _subscription;
-  std::unique_ptr<LanguageDetectionController::DetectionDetails>
+  std::unique_ptr<translate::LanguageDetectionDetails>
       _language_detection_details;
 }
 @end
@@ -312,26 +312,22 @@ using translate::LanguageDetectionController;
 
 - (void)setUp {
   [super setUp];
-  // Creates a LanguageDetectionController::Callback. The callback is deleted in
-  // tearDown.
-  LanguageDetectionController::Callback copyDetailsCallback =
-      base::BindBlockArc(^(
-          const LanguageDetectionController::DetectionDetails& details) {
-        _language_detection_details.reset(
-            new LanguageDetectionController::DetectionDetails(details));
+  language::IOSLanguageDetectionTabHelper::Callback copyDetailsCallback =
+      base::BindBlockArc(^(const translate::LanguageDetectionDetails& details) {
+        _language_detection_details =
+            base::MakeUnique<translate::LanguageDetectionDetails>(details);
       });
 
-  ChromeIOSTranslateClient* client = ChromeIOSTranslateClient::FromWebState(
-      chrome_test_util::GetCurrentWebState());
-  translate::IOSTranslateDriver* driver =
-      static_cast<translate::IOSTranslateDriver*>(client->GetTranslateDriver());
-  _subscription = driver->language_detection_controller()
-                      ->RegisterLanguageDetectionCallback(copyDetailsCallback);
+  language::IOSLanguageDetectionTabHelper::FromWebState(
+      chrome_test_util::GetCurrentWebState())
+      ->SetExtraCallbackForTesting(copyDetailsCallback);
 }
 
 - (void)tearDown {
-  DCHECK(_subscription);
-  _subscription.reset();
+  language::IOSLanguageDetectionTabHelper::FromWebState(
+      chrome_test_util::GetCurrentWebState())
+      ->SetExtraCallbackForTesting(
+          language::IOSLanguageDetectionTabHelper::Callback());
   _language_detection_details.reset();
   // TODO(crbug.com/642892): Investigate moving into test-specific teardown.
   // Re-enable translate.
@@ -360,7 +356,7 @@ using translate::LanguageDetectionController;
       GetFrenchPageHtml(kHtmlAttributeWithDeLang, kMetaItContentLanguage);
   web::test::SetUpSimpleHttpServer(responses);
 
-  LanguageDetectionController::DetectionDetails expectedLanguageDetails;
+  translate::LanguageDetectionDetails expectedLanguageDetails;
   expectedLanguageDetails.content_language = "it";
   expectedLanguageDetails.html_root_language = "de";
   expectedLanguageDetails.adopted_language = translate::kUnknownLanguageCode;
@@ -381,7 +377,7 @@ using translate::LanguageDetectionController;
 
   [ChromeEarlGrey loadURL:URL];
   // Check for no language detected.
-  LanguageDetectionController::DetectionDetails expectedLanguageDetails;
+  translate::LanguageDetectionDetails expectedLanguageDetails;
   expectedLanguageDetails.adopted_language = translate::kUnknownLanguageCode;
   [self assertLanguageDetails:expectedLanguageDetails];
 }
@@ -428,7 +424,7 @@ using translate::LanguageDetectionController;
 
   [ChromeEarlGrey loadURL:URL];
   // Check for no language detected.
-  LanguageDetectionController::DetectionDetails expectedLanguageDetails;
+  translate::LanguageDetectionDetails expectedLanguageDetails;
   expectedLanguageDetails.adopted_language = "und";
   [self assertLanguageDetails:expectedLanguageDetails];
   // Change the text of the page.
@@ -467,7 +463,7 @@ using translate::LanguageDetectionController;
 
   [ChromeEarlGrey loadURL:URL];
   // Check that language has been detected.
-  LanguageDetectionController::DetectionDetails expectedLanguageDetails;
+  translate::LanguageDetectionDetails expectedLanguageDetails;
   expectedLanguageDetails.adopted_language = "fr";
   [self assertLanguageDetails:expectedLanguageDetails];
   // Trigger the hash change.
@@ -482,7 +478,7 @@ using translate::LanguageDetectionController;
   // Start the HTTP server.
   std::unique_ptr<web::DataResponseProvider> provider(new TestResponseProvider);
   web::test::SetUpHttpServer(std::move(provider));
-  LanguageDetectionController::DetectionDetails expectedLanguageDetails;
+  translate::LanguageDetectionDetails expectedLanguageDetails;
 
   // The HTTP header is detected.
   GURL URL = web::test::HttpServer::MakeUrl(std::string("http://") +
@@ -522,7 +518,7 @@ using translate::LanguageDetectionController;
   // Start the HTTP server.
   std::unique_ptr<web::DataResponseProvider> provider(new TestResponseProvider);
   web::test::SetUpHttpServer(std::move(provider));
-  LanguageDetectionController::DetectionDetails expectedLanguageDetails;
+  translate::LanguageDetectionDetails expectedLanguageDetails;
 
   // Detection works when clicking on a link.
   GURL URL = web::test::HttpServer::MakeUrl(std::string("http://") + kLinkPath);
@@ -557,7 +553,7 @@ using translate::LanguageDetectionController;
   [ChromeEarlGrey loadURL:URL];
 
   // Check that language has been detected.
-  LanguageDetectionController::DetectionDetails expectedLanguageDetails;
+  translate::LanguageDetectionDetails expectedLanguageDetails;
   expectedLanguageDetails.html_root_language = "fr";
   expectedLanguageDetails.adopted_language = "fr";
   [self assertLanguageDetails:expectedLanguageDetails];
@@ -815,7 +811,7 @@ using translate::LanguageDetectionController;
 
 // Waits until a language has been detected and checks the language details.
 - (void)assertLanguageDetails:
-    (const LanguageDetectionController::DetectionDetails&)expectedDetails {
+    (const translate::LanguageDetectionDetails&)expectedDetails {
   GREYAssert(testing::WaitUntilConditionOrTimeout(
                  2.0,
                  ^{
@@ -823,7 +819,7 @@ using translate::LanguageDetectionController;
                  }),
              @"Language not detected");
 
-  LanguageDetectionController::DetectionDetails details =
+  translate::LanguageDetectionDetails details =
       *_language_detection_details.get();
   _language_detection_details.reset();
 

ios/web_view/internal/translate/cwv_translation_controller.mm

@@ -72,6 +72,13 @@ const NSInteger CWVTranslationErrorScriptLoadError =
   _webState = webState;
 
   ios_web_view::WebViewTranslateClient::CreateForWebState(_webState);
+  language::IOSLanguageDetectionTabHelper::CreateForWebState(
+      _webState,
+      ios_web_view::WebViewTranslateClient::FromWebState(_webState)
+          ->GetTranslateDriver()
+          ->CreateLanguageDetectionCallback(),
+      nullptr /* url_language_histogram */);
+
   _translateClient =
       ios_web_view::WebViewTranslateClient::FromWebState(_webState);
   _translateClient->set_translation_controller(self);

ios/web_view/internal/translate/web_view_translate_client.h

@@ -53,14 +53,8 @@ class WebViewTranslateClient
     return translate_manager_.get();
   }
 
- private:
-  friend class web::WebStateUserData<WebViewTranslateClient>;
-
-  // The lifetime of WebViewTranslateClient is managed by WebStateUserData.
-  explicit WebViewTranslateClient(web::WebState* web_state);
-
   // TranslateClient implementation.
-  translate::TranslateDriver* GetTranslateDriver() override;
+  translate::IOSTranslateDriver* GetTranslateDriver() override;
   PrefService* GetPrefs() override;
   std::unique_ptr<translate::TranslatePrefs> GetTranslatePrefs() override;
   translate::TranslateAcceptLanguages* GetTranslateAcceptLanguages() override;
@@ -79,6 +73,12 @@ class WebViewTranslateClient
   bool IsTranslatableURL(const GURL& url) override;
   void ShowReportLanguageDetectionErrorUI(const GURL& report_url) override;
 
+ private:
+  friend class web::WebStateUserData<WebViewTranslateClient>;
+
+  // The lifetime of WebViewTranslateClient is managed by WebStateUserData.
+  explicit WebViewTranslateClient(web::WebState* web_state);
+
   // web::WebStateObserver implementation.
   void WebStateDestroyed(web::WebState* web_state) override;
 

ios/web_view/internal/translate/web_view_translate_client.mm

@@ -56,8 +56,7 @@ WebViewTranslateClient::WebViewTranslateClient(web::WebState* web_state)
           nullptr /* language_model */)),
       translate_driver_(web_state,
                         web_state->GetNavigationManager(),
-                        translate_manager_.get(),
-                        nullptr /* language_histogram */) {}
+                        translate_manager_.get()) {}
 
 WebViewTranslateClient::~WebViewTranslateClient() = default;
 
@@ -82,7 +81,7 @@ void WebViewTranslateClient::ShowTranslateUI(
                              triggeredFromMenu:triggered_from_menu];
 }
 
-translate::TranslateDriver* WebViewTranslateClient::GetTranslateDriver() {
+translate::IOSTranslateDriver* WebViewTranslateClient::GetTranslateDriver() {
   return &translate_driver_;
 }