Add a feature which, when enabled, blocks permissions after X prompt dismissals.

chrome/browser/permissions/permission_context_base.cc

Index: chrome/browser/permissions/permission_context_base.cc
diff --git a/chrome/browser/permissions/permission_context_base.cc b/chrome/browser/permissions/permission_context_base.cc
index 8ce7f18b287fe0885a835bc862d313c02bbf2370..a8bb8fc8efa285f34f8e3264b6ab4317641dc0e8 100644
--- a/chrome/browser/permissions/permission_context_base.cc
+++ b/chrome/browser/permissions/permission_context_base.cc
@@ -36,9 +36,10 @@
 // static
 const char PermissionContextBase::kPermissionsKillSwitchFieldStudy[] =
     "PermissionsKillSwitch";
-// static
 const char PermissionContextBase::kPermissionsKillSwitchBlockedValue[] =
     "blocked";
+base::LazyInstance<PermissionPromptDecisionLog>
+    PermissionContextBase::prompt_decision_log_ = LAZY_INSTANCE_INITIALIZER;
 
 PermissionContextBase::PermissionContextBase(
     Profile* profile,
@@ -233,6 +234,15 @@ void PermissionContextBase::PermissionDecided(
   }
 #endif
 
+  // Check if we should convert a dismiss decision into a block decision. This
+  // is gated on enabling the kBlockPromptsIfDismissedOften feature.
+  if (!persist &&
+      prompt_decision_log_.Get().ShouldChangeDismissalToBlock(
+          profile_, requesting_origin, permission_type_)) {
+    persist = true;
+    content_setting = CONTENT_SETTING_BLOCK;
+  }
+
   NotifyPermissionSet(id, requesting_origin, embedding_origin, callback,
                       persist, content_setting);
 }