Expose way to enable/disable translate.

ios/web_view/internal/cwv_preferences.mm

Index: ios/web_view/internal/cwv_preferences.mm
diff --git a/ios/web_view/internal/cwv_preferences.mm b/ios/web_view/internal/cwv_preferences.mm
new file mode 100644
index 0000000000000000000000000000000000000000..e64376c92f2f0933da1deac29d0b3f66fdc28306
--- /dev/null
+++ b/ios/web_view/internal/cwv_preferences.mm
@@ -0,0 +1,48 @@
+// 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.
+
+#import "ios/web_view/public/cwv_preferences.h"

[michaeldo, 2017/07/14 16:11:08]

No need for cwv_preferences import. Other objects like this in web_view/ only
include the _internal.h header.

Ref:
https://cs.chromium.org/chromium/src/ios/web_view/internal/cwv_html_element.m...

[jzw1, 2017/07/14 17:37:19]

Done.

+#import "ios/web_view/internal/cwv_preferences_internal.h"
+
+#include "components/prefs/pref_service.h"
+#include "components/translate/core/browser/translate_pref_names.h"
+#include "components/translate/core/browser/translate_prefs.h"
+#include "ios/web_view/internal/pref_names.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation CWVPreferences {
+  PrefService* _prefService;
+}
+
+@dynamic translationEnabled;

[michaeldo, 2017/07/14 16:11:08]

I don't think @dynamic is needed here because both the setter and getters are
defined in this method, is it?

Ref: http://www.ios-blog.co.uk/tutorials/objective-c/synthesize-vs-dynamic/

[jzw1, 2017/07/14 17:37:19]

Oh yeah, I guess I've been doing it wrong for a long time :P

[michaeldo, 2017/07/14 17:39:32]

Thanks. No worries, I was only trying to learn why it was used here myself since
I've only used it with CoreData. :)

+
+- (instancetype)initWithPrefService:(PrefService*)prefService {
+  self = [super init];
+  if (self) {
+    _prefService = prefService;
+  }
+  return self;
+}
+
+#pragma mark - Public Methods
+
+- (void)setTranslationEnabled:(BOOL)enabled {
+  _prefService->SetBoolean(prefs::kEnableTranslate, enabled);
+}
+
+- (BOOL)isTranslationEnabled {
+  return _prefService->GetBoolean(prefs::kEnableTranslate);
+}
+
+- (void)resetTranslationSettings {
+  translate::TranslatePrefs translatePrefs(
+      _prefService, prefs::kAcceptLanguages,
+      /*preferred_languages_pref=*/nullptr);
+  translatePrefs.ResetToDefaults();
+}
+
+@end