Remove CWV class and move setting User Agent to CWVWebViewConfiguration.

ios/web_view/internal/web_view_web_main_parts.mm

Index: ios/web_view/internal/web_view_web_main_parts.mm
diff --git a/ios/web_view/internal/web_view_web_main_parts.mm b/ios/web_view/internal/web_view_web_main_parts.mm
index dede48ebe8bb539a0fad88f2bc207ad82d2af790..67218afe0a6b1b22d86720341b180db748916461 100644
--- a/ios/web_view/internal/web_view_web_main_parts.mm
+++ b/ios/web_view/internal/web_view_web_main_parts.mm
@@ -9,8 +9,6 @@
 #include "base/base_paths.h"
 #include "base/memory/ptr_util.h"
 #include "base/path_service.h"
-#include "components/translate/core/browser/translate_download_manager.h"
-#include "ios/web_view/internal/web_view_browser_state.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 #include "ui/base/resource/resource_bundle.h"
 
@@ -34,18 +32,6 @@ void WebViewWebMainParts::PreMainMessageLoopRun() {
   pak_file = pak_file.Append(FILE_PATH_LITERAL("web_view_resources.pak"));
   ui::ResourceBundle::GetSharedInstance().AddDataPackFromPath(
       pak_file, ui::SCALE_FACTOR_NONE);
-
-  browser_state_ = base::MakeUnique<WebViewBrowserState>(false);
-  off_the_record_browser_state_ = base::MakeUnique<WebViewBrowserState>(true);
-
-  // Initialize translate.
-  translate::TranslateDownloadManager* download_manager =
-      translate::TranslateDownloadManager::GetInstance();
-  // TODO(crbug.com/679895): See if we need the system request context here.
-  download_manager->set_request_context(browser_state_->GetRequestContext());
-  // TODO(crbug.com/679895): Bring up application locale correctly.
-  download_manager->set_application_locale(l10n_util::GetLocaleOverride());
-  download_manager->language_list()->SetResourceRequestsAllowed(true);
 }
 
 }  // namespace ios_web_view