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

chrome/browser/plugins/plugins_field_trial.cc

Index: chrome/browser/plugins/plugins_field_trial.cc
diff --git a/chrome/browser/plugins/plugins_field_trial.cc b/chrome/browser/plugins/plugins_field_trial.cc
index 68d3d957432c554b800687e63d6a6b089bdb82cd..3dc9e27f50248d2c5c2221ec4ffdcfa0e47c480f 100644
--- a/chrome/browser/plugins/plugins_field_trial.cc
+++ b/chrome/browser/plugins/plugins_field_trial.cc
@@ -5,7 +5,33 @@
 #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(
@@ -22,3 +48,11 @@ ContentSetting PluginsFieldTrial::EffectiveContentSetting(
              ? 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();
+}