Add metrics for user manually added exceptions

chrome/browser/ui/webui/options/content_settings_handler.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/webui/options/content_settings_handler.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/content_settings/web_site_settings_uma_util.h"
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
@@ skipping 1496 matching lines @@
 
     ContentSetting setting_type;
     bool result =
         content_settings::ContentSettingFromString(setting, &setting_type);
     DCHECK(result);
 
     settings_map->SetContentSettingCustomScope(
         ContentSettingsPattern::FromString(pattern),
         ContentSettingsPattern::Wildcard(), type, std::string(), setting_type);
     WebSiteSettingsUmaUtil::LogPermissionChange(type, setting_type);
+
+    size_t num_values;
+    int histogram_value = ContentSettingTypeToHistogramValue(type, &num_values);
+    UMA_HISTOGRAM_ENUMERATION("ContentSettings.AddManualException",
+                              histogram_value, num_values);

[raymes, 2016/04/12 23:22:39]

Do you think this histogram will be useful?

[lshang, 2016/04/14 04:55:29]

Done.

   }
 }
 
 void ContentSettingsHandler::CheckExceptionPatternValidity(
     const base::ListValue* args) {
   std::string type_string;
   CHECK(args->GetString(0, &type_string));
   std::string mode_string;
   CHECK(args->GetString(1, &mode_string));
   std::string pattern_string;
@@ skipping 160 matching lines @@
 
   // Exceptions apply only when the feature is enabled.
   PrefService* prefs = user_prefs::UserPrefs::Get(GetBrowserContext(web_ui()));
   bool enable_exceptions = prefs->GetBoolean(prefs::kEnableDRM);
   web_ui()->CallJavascriptFunction(
       "ContentSettings.enableProtectedContentExceptions",
       base::FundamentalValue(enable_exceptions));
 }
 
 }  // namespace options