[IOS][Language] Language Settings - Histograms

Adds histograms for page impressions and actions identical to Android's.

Bug: 957688
Change-Id: I5985cca226c0ec15cdd67ed4dcf99a73a8876e9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1628031
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Peter Lee <pkl@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663741}

ios/chrome/browser/ui/settings/language/BUILD.gn

@@ -36,6 +36,7 @@ source_set("language_ui") {
     "language_settings_commands.h",
     "language_settings_consumer.h",
     "language_settings_data_source.h",
+    "language_settings_histograms.h",
     "language_settings_table_view_controller.h",
     "language_settings_table_view_controller.mm",
   ]

ios/chrome/browser/ui/settings/language/add_language_table_view_controller.mm

@@ -5,9 +5,11 @@
 #import "ios/chrome/browser/ui/settings/language/add_language_table_view_controller.h"
 
 #include "base/mac/foundation_util.h"
+#include "base/metrics/histogram_macros.h"
 #import "ios/chrome/browser/ui/list_model/list_item+Controller.h"
 #import "ios/chrome/browser/ui/settings/language/cells/language_item.h"
 #import "ios/chrome/browser/ui/settings/language/language_settings_data_source.h"
+#import "ios/chrome/browser/ui/settings/language/language_settings_histograms.h"
 #import "ios/chrome/browser/ui/table_view/table_view_navigation_controller_constants.h"
 #include "ios/chrome/browser/ui/ui_feature_flags.h"
 #import "ios/chrome/browser/ui/util/uikit_ui_util.h"
@@ -75,6 +77,9 @@ - (instancetype)initWithDataSource:(id<LanguageSettingsDataSource>)dataSource
   if (self) {
     _dataSource = dataSource;
     _delegate = delegate;
+
+    UMA_HISTOGRAM_ENUMERATION(kLanguageSettingsPageImpressionHistogram,
+                              LanguageSettingsPages::PAGE_ADD_LANGUAGE);
   }
   return self;
 }

ios/chrome/browser/ui/settings/language/language_details_table_view_controller.mm

@@ -5,9 +5,11 @@
 #import "ios/chrome/browser/ui/settings/language/language_details_table_view_controller.h"
 
 #include "base/feature_list.h"
+#include "base/metrics/histogram_macros.h"
 #import "ios/chrome/browser/ui/settings/cells/settings_cells_constants.h"
 #import "ios/chrome/browser/ui/settings/language/cells/language_item.h"
 #import "ios/chrome/browser/ui/settings/language/language_settings_data_source.h"
+#import "ios/chrome/browser/ui/settings/language/language_settings_histograms.h"
 #import "ios/chrome/browser/ui/table_view/cells/table_view_cells_constants.h"
 #import "ios/chrome/browser/ui/table_view/cells/table_view_text_item.h"
 #include "ios/chrome/browser/ui/ui_feature_flags.h"
@@ -62,6 +64,9 @@ - (instancetype)initWithLanguageItem:(LanguageItem*)languageItem
   if (self) {
     _languageItem = languageItem;
     _delegate = delegate;
+
+    UMA_HISTOGRAM_ENUMERATION(kLanguageSettingsPageImpressionHistogram,
+                              LanguageSettingsPages::PAGE_LANGUAGE_DETAILS);
   }
   return self;
 }

ios/chrome/browser/ui/settings/language/language_settings_histograms.h

@@ -0,0 +1,41 @@
+// Copyright 2019 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 IOS_CHROME_BROWSER_UI_SETTINGS_LANGUAGE_LANGUAGE_SETTINGS_HISTOGRAMS_H_
+#define IOS_CHROME_BROWSER_UI_SETTINGS_LANGUAGE_LANGUAGE_SETTINGS_HISTOGRAMS_H_
+
+// UMA histogram names. These constants are repeated in LanguagesManager.java.
+const char kLanguageSettingsPageImpressionHistogram[] =
+    "LanguageSettings.PageImpression";
+const char kLanguageSettingsActionsHistogram[] = "LanguageSettings.Actions";
+
+// Enum for the LanguageSettings.PageImpression histogram. These constants are
+// repeated in LanguagesManager.java.
+// Note: This enum is append-only. Keep in sync with "LanguageSettingsPageType"
+// in src/tools/metrics/histograms/enums.xml.
+enum class LanguageSettingsPages {
+  PAGE_MAIN = 0,
+  PAGE_ADD_LANGUAGE = 1,
+  PAGE_LANGUAGE_DETAILS = 2,
+  kMaxValue = PAGE_LANGUAGE_DETAILS,
+};
+
+// Enum for the LanguageSettings.Actions histogram. These constants are repeated
+// in LanguagesManager.java.
+// Note: This enum is append-only. Keep in sync with
+// "LanguageSettingsActionType" in src/tools/metrics/histograms/enums.xml.
+enum class LanguageSettingsActions {
+  UNKNOWN = 0,  // Never logged.
+  CLICK_ON_ADD_LANGUAGE = 1,
+  LANGUAGE_ADDED = 2,
+  LANGUAGE_REMOVED = 3,
+  DISABLE_TRANSLATE_GLOBALLY = 4,
+  ENABLE_TRANSLATE_GLOBALLY = 5,
+  DISABLE_TRANSLATE_FOR_SINGLE_LANGUAGE = 6,
+  ENABLE_TRANSLATE_FOR_SINGLE_LANGUAGE = 7,
+  LANGUAGE_LIST_REORDERED = 8,
+  kMaxValue = LANGUAGE_LIST_REORDERED,
+};
+
+#endif  // IOS_CHROME_BROWSER_UI_SETTINGS_LANGUAGE_LANGUAGE_SETTINGS_HISTOGRAMS_H_

ios/chrome/browser/ui/settings/language/language_settings_mediator.mm

@@ -8,6 +8,7 @@
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/language/core/browser/language_model_manager.h"
 #include "components/language/core/browser/pref_names.h"
@@ -24,6 +25,7 @@
 #include "ios/chrome/browser/translate/translate_service_ios.h"
 #import "ios/chrome/browser/ui/settings/language/cells/language_item.h"
 #import "ios/chrome/browser/ui/settings/language/language_settings_consumer.h"
+#import "ios/chrome/browser/ui/settings/language/language_settings_histograms.h"
 #import "ios/chrome/browser/ui/settings/utils/observable_boolean.h"
 #import "ios/chrome/browser/ui/settings/utils/pref_backed_boolean.h"
 #include "ios/chrome/grit/ios_strings.h"
@@ -210,6 +212,11 @@ - (BOOL)translateEnabled {
 
 - (void)setTranslateEnabled:(BOOL)enabled {
   [self.translateEnabledPref setValue:enabled];
+
+  UMA_HISTOGRAM_ENUMERATION(
+      kLanguageSettingsActionsHistogram,
+      enabled ? LanguageSettingsActions::ENABLE_TRANSLATE_GLOBALLY
+              : LanguageSettingsActions::DISABLE_TRANSLATE_GLOBALLY);
 }
 
 - (void)moveLanguage:(const std::string&)languageCode
@@ -222,22 +229,39 @@ - (void)moveLanguage:(const std::string&)languageCode
   _translatePrefs->GetLanguageList(&languageCodes);
   _translatePrefs->RearrangeLanguage(languageCode, where, offset,
                                      languageCodes);
+
+  UMA_HISTOGRAM_ENUMERATION(kLanguageSettingsActionsHistogram,
+                            LanguageSettingsActions::LANGUAGE_LIST_REORDERED);
 }
 
 - (void)addLanguage:(const std::string&)languageCode {
   _translatePrefs->AddToLanguageList(languageCode, /*force_blocked=*/false);
+
+  UMA_HISTOGRAM_ENUMERATION(kLanguageSettingsActionsHistogram,
+                            LanguageSettingsActions::LANGUAGE_ADDED);
 }
 
 - (void)removeLanguage:(const std::string&)languageCode {
   _translatePrefs->RemoveFromLanguageList(languageCode);
+
+  UMA_HISTOGRAM_ENUMERATION(kLanguageSettingsActionsHistogram,
+                            LanguageSettingsActions::LANGUAGE_REMOVED);
 }
 
 - (void)blockLanguage:(const std::string&)languageCode {
   _translatePrefs->BlockLanguage(languageCode);
+
+  UMA_HISTOGRAM_ENUMERATION(
+      kLanguageSettingsActionsHistogram,
+      LanguageSettingsActions::DISABLE_TRANSLATE_FOR_SINGLE_LANGUAGE);
 }
 
 - (void)unblockLanguage:(const std::string&)languageCode {
   _translatePrefs->UnblockLanguage(languageCode);
+
+  UMA_HISTOGRAM_ENUMERATION(
+      kLanguageSettingsActionsHistogram,
+      LanguageSettingsActions::ENABLE_TRANSLATE_FOR_SINGLE_LANGUAGE);
 }
 
 #pragma mark - Private methods

ios/chrome/browser/ui/settings/language/language_settings_table_view_controller.mm

@@ -6,6 +6,7 @@
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
+#include "base/metrics/histogram_macros.h"
 #import "ios/chrome/browser/ui/list_model/list_item+Controller.h"
 #import "ios/chrome/browser/ui/settings/cells/settings_cells_constants.h"
 #import "ios/chrome/browser/ui/settings/cells/settings_switch_cell.h"
@@ -15,6 +16,7 @@
 #import "ios/chrome/browser/ui/settings/language/language_details_table_view_controller.h"
 #import "ios/chrome/browser/ui/settings/language/language_settings_commands.h"
 #import "ios/chrome/browser/ui/settings/language/language_settings_data_source.h"
+#import "ios/chrome/browser/ui/settings/language/language_settings_histograms.h"
 #import "ios/chrome/browser/ui/table_view/cells/table_view_cells_constants.h"
 #import "ios/chrome/browser/ui/table_view/cells/table_view_link_header_footer_item.h"
 #import "ios/chrome/browser/ui/table_view/cells/table_view_text_item.h"
@@ -87,6 +89,9 @@ - (instancetype)initWithDataSource:(id<LanguageSettingsDataSource>)dataSource
   if (self) {
     _dataSource = dataSource;
     _commandHandler = commandHandler;
+
+    UMA_HISTOGRAM_ENUMERATION(kLanguageSettingsPageImpressionHistogram,
+                              LanguageSettingsPages::PAGE_MAIN);
   }
   return self;
 }
@@ -199,6 +204,9 @@ - (void)tableView:(UITableView*)tableView
       break;
     }
     case ItemTypeAddLanguage: {
+      UMA_HISTOGRAM_ENUMERATION(kLanguageSettingsActionsHistogram,
+                                LanguageSettingsActions::CLICK_ON_ADD_LANGUAGE);
+
       AddLanguageTableViewController* viewController =
           [[AddLanguageTableViewController alloc]
               initWithDataSource:self.dataSource

tools/metrics/histograms/enums.xml

@@ -32131,6 +32131,7 @@ Called by update_gpu_driver_bug_workaround_entries.py.-->
 <enum name="LanguageSettingsPageType">
   <int value="0" label="Main"/>
   <int value="1" label="Add Language"/>
+  <int value="2" label="Language Details">iOS only.</int>
 </enum>
 
 <enum name="LargestContentType">