Hide TranslateManager from CWVTranslationController.

This is in preparation for a FakeWebViewTranslateClient so unit tests
can be written for the rest of the public methods.

Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I7bb15cf38467b5a2b388fee7849599c1876ffa6c
Reviewed-on: https://chromium-review.googlesource.com/953824Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: John Wu <jzw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541669}

ios/web_view/internal/translate/cwv_translation_controller.mm

@@ -10,7 +10,6 @@
 #include "base/strings/string16.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/translate/core/browser/translate_download_manager.h"
-#include "components/translate/core/browser/translate_manager.h"
 #import "ios/web_view/internal/cwv_web_view_configuration_internal.h"
 #import "ios/web_view/internal/translate/cwv_translation_language_internal.h"
 #import "ios/web_view/internal/translate/web_view_translate_client.h"
@@ -146,12 +145,12 @@ const NSInteger CWVTranslationErrorScriptLoadError =
       base::SysNSStringToUTF8(sourceLanguage.languageCode);
   std::string targetLanguageCode =
       base::SysNSStringToUTF8(targetLanguage.languageCode);
-  _translateClient->translate_manager()->TranslatePage(
-      sourceLanguageCode, targetLanguageCode, userInitiated);
+  _translateClient->TranslatePage(sourceLanguageCode, targetLanguageCode,
+                                  userInitiated);
 }
 
 - (void)revertTranslation {
-  _translateClient->translate_manager()->RevertTranslation();
+  _translateClient->RevertTranslation();
 }
 
 - (void)setTranslationPolicy:(CWVTranslationPolicy*)policy

ios/web_view/internal/translate/web_view_translate_client.h

@@ -51,9 +51,14 @@ class WebViewTranslateClient
     translation_controller_ = controller;
   }
 
-  translate::TranslateManager* translate_manager() {
-    return translate_manager_.get();
-  }
+  // Performs translation from |source_lang| to |target_lang|.
+  // |trigged_from_menu| indicates if a direct result of user interaction.
+  void TranslatePage(const std::string& source_lang,
+                     const std::string& target_lang,
+                     bool triggered_from_menu);
+
+  // Reverts previous translations back to original language.
+  void RevertTranslation();
 
   // TranslateClient implementation.
   translate::IOSTranslateDriver* GetTranslateDriver() override;

ios/web_view/internal/translate/web_view_translate_client.mm

@@ -55,6 +55,19 @@ WebViewTranslateClient::WebViewTranslateClient(web::WebState* web_state)
 
 WebViewTranslateClient::~WebViewTranslateClient() = default;
 
+void WebViewTranslateClient::TranslatePage(const std::string& source_lang,
+                                           const std::string& target_lang,
+                                           bool triggered_from_menu) {
+  DCHECK(translate_manager_);
+  translate_manager_->TranslatePage(source_lang, target_lang,
+                                    triggered_from_menu);
+}
+
+void WebViewTranslateClient::RevertTranslation() {
+  DCHECK(translate_manager_);
+  translate_manager_->RevertTranslation();
+}
+
 // TranslateClient implementation:
 
 std::unique_ptr<infobars::InfoBar> WebViewTranslateClient::CreateInfoBar(
@@ -124,6 +137,8 @@ void WebViewTranslateClient::ShowReportLanguageDetectionErrorUI(
   NOTREACHED();
 }
 
+// web::WebStateObserver implementation
+
 void WebViewTranslateClient::WebStateDestroyed(web::WebState* web_state) {
   web_state->RemoveObserver(this);
   // Translation process can be interrupted.