Implement DelegationTracker for tracking delegated permissions to RenderFrameHosts

content/public/browser/permission_type.h

Index: content/public/browser/permission_type.h
diff --git a/content/public/browser/permission_type.h b/content/public/browser/permission_type.h
index ec9e8c5c082a5091f060233212c1ca9261a4fc18..c2e8d1989f3b12d546bbef42a57df0316867fecb 100644
--- a/content/public/browser/permission_type.h
+++ b/content/public/browser/permission_type.h
@@ -28,6 +28,12 @@ enum class PermissionType {
   NUM,
 };
 
+struct PermissionTypeHash {
+  std::size_t operator()(const content::PermissionType& type) const {
+    return static_cast<size_t>(type);
+  }
+};
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PERMISSION_TYPE_H_