[HBD] Gate the advertising of Flash on Site Engagement.

chrome/browser/plugins/plugins_field_trial.cc

 // Copyright 2015 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/plugins/plugins_field_trial.h"
 
 #include "base/feature_list.h"
+#include "base/strings/string_number_conversions.h"
+#include "chrome/browser/engagement/site_engagement_service.h"
 #include "chrome/common/chrome_features.h"
+#include "components/content_settings/core/browser/host_content_settings_map.h"
+#include "components/variations/variations_associated_data.h"
+
+namespace {
+
+// The default site engagement threshold to allow Flash to be presented as an
+// available plugin.
+const double kSiteEngagementThresholdForFlash = 1.0;
+
+double GetSiteEngagementThresholdForFlash() {
+  double threshold = -1;
+  std::string param = variations::GetVariationParamValueByFeature(
+      features::kPreferHtmlOverPlugins,
+      PluginsFieldTrial::kSiteEngagementThresholdForFlashKey);
+  if (base::StringToDouble(param, &threshold) && threshold >= 0)
+    return threshold;
+  return kSiteEngagementThresholdForFlash;
+}
+
+}  // namespace
+
+// static
+const char* PluginsFieldTrial::kSiteEngagementThresholdForFlashKey =
+    "engagement_threshold_for_flash";
 
 // static
 ContentSetting PluginsFieldTrial::EffectiveContentSetting(
     ContentSettingsType type,
     ContentSetting setting) {
   if (type != CONTENT_SETTINGS_TYPE_PLUGINS ||
       setting != ContentSetting::CONTENT_SETTING_ASK) {
     return setting;
   }
 
   // For Plugins, ASK is obsolete. Show as BLOCK or, if PreferHtmlOverPlugins
   // feature is enabled, as DETECT_IMPORTANT_CONTENT to reflect actual behavior.
   return base::FeatureList::IsEnabled(features::kPreferHtmlOverPlugins)
              ? ContentSetting::CONTENT_SETTING_DETECT_IMPORTANT_CONTENT
              : ContentSetting::CONTENT_SETTING_BLOCK;
 }
+
+// static
+bool PluginsFieldTrial::HasSufficientEngagementForFlash(
+    HostContentSettingsMap* settings,
+    const GURL& url) {
+  return SiteEngagementService::GetScoreFromSettings(settings, url) >=
+         GetSiteEngagementThresholdForFlash();
+}