Implement <webview>.addContentScript/removeContentScript API [1]

extensions/renderer/resources/guest_view/web_view_experimental.js

Index: extensions/renderer/resources/guest_view/web_view_experimental.js
diff --git a/extensions/renderer/resources/guest_view/web_view_experimental.js b/extensions/renderer/resources/guest_view/web_view_experimental.js
index 6214eda742e1c6dd25afa47b76fd5e998948978f..f8420c06256a6a0d6d75663a7b6ba5a03d391502 100644
--- a/extensions/renderer/resources/guest_view/web_view_experimental.js
+++ b/extensions/renderer/resources/guest_view/web_view_experimental.js
@@ -30,10 +30,30 @@ WebViewImpl.prototype.loadDataWithBaseUrl = function(
       });
 };
 
+WebViewImpl.prototype.addContentScripts = function() {
+  if (!this.guest.getId()) {
+    window.console.error(WebViewConstants.ERROR_MSG_CANNOT_INJECT_SCRIPT);
+    return false;
+  }
+  var args = $Array.concat([this.guest.getId()], $Array.slice(arguments));
+  return $Function.apply(WebViewInternal.addContentScripts, null, args);
+};
+
+WebViewImpl.prototype.removeContentScripts = function(var_args) {
+  if (!this.guest.getId()) {
+    window.console.error(WebViewConstants.ERROR_MSG_CANNOT_INJECT_SCRIPT);
+    return false;
+  }
+  var args = $Array.concat([this.guest.getId()], $Array.slice(arguments));
+  return $Function.apply(WebViewInternal.removeContentScripts, null, args);
+};
+
 // An array of <webview>'s experimental API methods. See |WEB_VIEW_API_METHODS|
 // in web_view_api_methods.js for more details.
 var WEB_VIEW_EXPERIMENTAL_API_METHODS = [
-  'loadDataWithBaseUrl'
+  'loadDataWithBaseUrl',
+  'addContentScripts',
+  'removeContentScripts'
 ];
 
 // Registers the experimantal WebVIew API when available.