[
  {
    "namespace": "manifest",
    "types": [
      {
        "$extend": "WebExtensionManifest",
        "properties": {
          "chrome_settings_overrides": {
            "type": "object",
            "optional": true,
            "additionalProperties": { "$ref": "UnrecognizedProperty" },
            "properties": {
              "homepage": {
                "type": "string",
                "format": "relativeUrl",
                "optional": true,
                "preprocess": "localize"
              },
             "search_provider": {
                "type": "object",
                "optional": true,
                "additionalProperties": { "$ref": "UnrecognizedProperty" },
                "properties": {
                  "name": {
                    "type": "string",
                    "preprocess": "localize"
                  },
                  "keyword": {
                    "type": "string",
                    "optional": true,
                    "preprocess": "localize"
                  },
                  "search_url": {
                    "type": "string",
                    "format": "url",
                    "pattern": "^https://.*$",
                    "preprocess": "localize"
                  },
                  "favicon_url": {
                    "type": "string",
                    "optional": true,
                    "format": "url",
                    "preprocess": "localize"
                  },
                  "suggest_url": {
                    "type": "string",
                    "optional": true,
                    "format": "url",
                    "preprocess": "localize"
                  },
                  "instant_url": {
                    "type": "string",
                    "optional": true,
                    "format": "url",
                    "preprocess": "localize",
                    "deprecated": "Unsupported on Firefox at this time."
                  },
                  "image_url": {
                    "type": "string",
                    "optional": true,
                    "format": "url",
                    "preprocess": "localize",
                    "deprecated": "Unsupported on Firefox at this time."
                  },
                  "search_url_post_params": {
                    "type": "string",
                    "optional": true,
                    "preprocess": "localize",
                    "deprecated": "Unsupported on Firefox at this time."
                  },
                  "instant_url_post_params": {
                    "type": "string",
                    "optional": true,
                    "preprocess": "localize",
                    "deprecated": "Unsupported on Firefox at this time."
                  },
                  "image_url_post_params": {
                    "type": "string",
                    "optional": true,
                    "preprocess": "localize",
                    "deprecated": "Unsupported on Firefox at this time."
                  },
                  "alternate_urls": {
                    "type": "array",
                    "items": {
                      "type": "string",
                      "format": "url",
                      "preprocess": "localize"
                    },
                    "optional": true,
                    "deprecated": "Unsupported on Firefox at this time."
                  },
                  "prepopulated_id": {
                    "type": "integer",
                    "optional": true,
                    "deprecated": "Unsupported on Firefox."
                  },
                  "is_default": {
                    "type": "boolean",
                    "optional": true,
                    "description": "Sets the default engine to a built-in engine only."
                  }
                }
              }
            }
          }
        }
      }
    ]
  }
]