Expose method to reset translate settings.

Had to refactor browser states to be global instances and force off the record
browser state to use an in-memory store instead of a json file persisted on disk.

BUG=739987

Review-Url: https://codereview.chromium.org/2965303002
Cr-Commit-Position: refs/heads/master@{#485392}

ios/web_view/internal/cwv_web_view_configuration.mm

@@ -7,7 +7,6 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_restrictions.h"
-#include "components/translate/core/browser/translate_download_manager.h"
 #include "ios/web_view/internal/app/application_context.h"
 #import "ios/web_view/internal/cwv_user_content_controller_internal.h"
 #include "ios/web_view/internal/web_view_browser_state.h"
@@ -32,14 +31,27 @@
 @synthesize userContentController = _userContentController;
 
 + (instancetype)defaultConfiguration {
-  auto browserState =
-      base::MakeUnique<ios_web_view::WebViewBrowserState>(false);
-  return [[self alloc] initWithBrowserState:std::move(browserState)];
+  static CWVWebViewConfiguration* defaultConfiguration;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    auto browserState =
+        base::MakeUnique<ios_web_view::WebViewBrowserState>(false);
+    defaultConfiguration =
+        [[self alloc] initWithBrowserState:std::move(browserState)];
+  });
+  return defaultConfiguration;
 }
 
 + (instancetype)incognitoConfiguration {
-  auto browserState = base::MakeUnique<ios_web_view::WebViewBrowserState>(true);
-  return [[self alloc] initWithBrowserState:std::move(browserState)];
+  static CWVWebViewConfiguration* incognitoConfiguration;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    auto browserState =
+        base::MakeUnique<ios_web_view::WebViewBrowserState>(true);
+    incognitoConfiguration =
+        [[self alloc] initWithBrowserState:std::move(browserState)];
+  });
+  return incognitoConfiguration;
 }
 
 + (void)initialize {
@@ -62,10 +74,14 @@
   return self;
 }
 
+#pragma mark - Public Methods
+
 - (BOOL)isPersistent {
   return !_browserState->IsOffTheRecord();
 }
 
+#pragma mark - Private Methods
+
 - (ios_web_view::WebViewBrowserState*)browserState {
   return _browserState.get();
 }

ios/web_view/internal/translate/cwv_translation_controller.mm

@@ -11,8 +11,11 @@
 #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"
+#include "ios/web_view/internal/pref_names.h"
 #import "ios/web_view/internal/translate/cwv_translation_language_internal.h"
 #import "ios/web_view/internal/translate/web_view_translate_client.h"
+#include "ios/web_view/internal/web_view_browser_state.h"
 #import "ios/web_view/public/cwv_translation_controller_delegate.h"
 #import "ios/web_view/public/cwv_translation_policy.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -65,6 +68,17 @@ const NSInteger CWVTranslationErrorScriptLoadError =
 @synthesize supportedLanguagesByCode = _supportedLanguagesByCode;
 @synthesize webState = _webState;
 
+#pragma mark - Class Methods
+
++ (void)resetTranslationPolicies {
+  CWVWebViewConfiguration* configuration =
+      [CWVWebViewConfiguration defaultConfiguration];
+  PrefService* prefService = configuration.browserState->GetPrefs();
+  translate::TranslatePrefs translatePrefs(prefService, prefs::kAcceptLanguages,
+                                           nullptr);
+  translatePrefs.ResetToDefaults();
+}
+
 #pragma mark - Internal Methods
 
 - (void)setWebState:(web::WebState*)webState {
@@ -155,6 +169,7 @@ const NSInteger CWVTranslationErrorScriptLoadError =
 
 - (void)setTranslationPolicy:(CWVTranslationPolicy*)policy
              forPageLanguage:(CWVTranslationLanguage*)pageLanguage {
+  DCHECK(!_webState->GetBrowserState()->IsOffTheRecord());
   std::string languageCode = base::SysNSStringToUTF8(pageLanguage.languageCode);
   switch (policy.type) {
     case CWVTranslationPolicyAsk: {
@@ -198,6 +213,7 @@ const NSInteger CWVTranslationErrorScriptLoadError =
 
 - (void)setTranslationPolicy:(CWVTranslationPolicy*)policy
                  forPageHost:(NSString*)pageHost {
+  DCHECK(!_webState->GetBrowserState()->IsOffTheRecord());
   DCHECK(pageHost.length);
   switch (policy.type) {
     case CWVTranslationPolicyAsk: {

ios/web_view/internal/web_view_browser_state.mm

@@ -8,11 +8,13 @@
 
 #include "base/base_paths.h"
 #include "base/files/file_path.h"
+#include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
 #include "base/sequenced_task_runner.h"
 #include "base/threading/thread_restrictions.h"
 #include "components/pref_registry/pref_registry_syncable.h"
+#include "components/prefs/in_memory_pref_store.h"
 #include "components/prefs/json_pref_store.h"
 #include "components/prefs/pref_filter.h"
 #include "components/prefs/pref_service_factory.h"
@@ -56,8 +58,13 @@ WebViewBrowserState::WebViewBrowserState(bool off_the_record)
       JsonPrefStore::GetTaskRunnerForFile(path_,
                                           web::WebThread::GetBlockingPool());
 
-  scoped_refptr<PersistentPrefStore> user_pref_store = new JsonPrefStore(
-      path_.Append(kPreferencesFilename), sequenced_task_runner, nullptr);
+  scoped_refptr<PersistentPrefStore> user_pref_store;
+  if (off_the_record) {
+    user_pref_store = new InMemoryPrefStore();
+  } else {
+    user_pref_store = new JsonPrefStore(path_.Append(kPreferencesFilename),
+                                        sequenced_task_runner, nullptr);
+  }
 
   PrefServiceFactory factory;
   factory.set_user_prefs(user_pref_store);

ios/web_view/public/cwv_translation_controller.h

@@ -52,6 +52,10 @@ CWV_EXPORT
 @property(nonatomic, readonly)
     NSSet<CWVTranslationLanguage*>* supportedLanguages;
 
+// Resets all translation policies to default (CWVTranslationPolicyAsk).
+// Only resets non-incognito settings.
++ (void)resetTranslationPolicies;
+
 // Begins translation on the current page from |sourceLanguage| to
 // |targetLanguage|. These language parameters must be chosen from
 // |supportedLanguages|. Set |userInitiated| to YES if translation
@@ -70,6 +74,7 @@ CWV_EXPORT
 
 // Sets or retrieves translation policies associated with a specified language.
 // |pageLanguage| should be the language code of the language.
+// Not supported in incognito mode.
 - (void)setTranslationPolicy:(CWVTranslationPolicy*)policy
              forPageLanguage:(CWVTranslationLanguage*)pageLanguage;
 - (CWVTranslationPolicy*)translationPolicyForPageLanguage:
@@ -77,6 +82,7 @@ CWV_EXPORT
 
 // Sets or retrieves translation policies associated with a specified page.
 // |pageHost| should be the hostname of the website. Must not be empty.
+// Not supported in incognito mode.
 - (void)setTranslationPolicy:(CWVTranslationPolicy*)policy
                  forPageHost:(NSString*)pageHost;
 - (CWVTranslationPolicy*)translationPolicyForPageHost:(NSString*)pageHost;