Use asserts in origin trials layout tests

third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added.html

Index: third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added.html b/third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added.html
index ff7144d134281c8a693b27582507be664354aaa4..9c473449f185991fca7f827278bc95a15621b771 100644
--- a/third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added.html
+++ b/third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added.html
@@ -9,21 +9,15 @@
 // generate_token.py  http://127.0.0.1:8000 ImageCapture --expire-timestamp=2000000000
 var token = "AgnhzY0dhvMKsSPYNWHltCxTsLpVFzM/H0rZdpY4DeVo7ry4xm8VLRJU5aVLy+wSgnUa34pTTR017JFu4qnUAQwAAABUeyJvcmlnaW4iOiAiaHR0cDovLzEyNy4wLjAuMTo4MDAwIiwgImZlYXR1cmUiOiAiSW1hZ2VDYXB0dXJlIiwgImV4cGlyeSI6IDIwMDAwMDAwMDB9";
 
+let interfaces_to_check = ['ImageCapture','MediaSettingsRange','PhotoCapabilities'];
+
 test(t => {
-  var interfaces =
-      OriginTrialsHelper.get_interface_names(this, ['ImageCapture',
-                                                    'MediaSettingsRange',
-                                                    'PhotoCapabilities']);
-  console.log('Interfaces before adding trial token\n' + interfaces);
+  OriginTrialsHelper.check_interfaces_missing(this, interfaces_to_check);
 }, "ImageCapture related interfaces before adding trial token via script.");
 
 OriginTrialsHelper.add_token(token);
 
 test(t => {
-  var interfaces =
-      OriginTrialsHelper.get_interface_names(this, ['ImageCapture',
-                                                    'MediaSettingsRange',
-                                                    'PhotoCapabilities']);
-  console.log('Interfaces after adding trial token\n' + interfaces);
+  OriginTrialsHelper.check_interfaces(this, interfaces_to_check);
 }, "ImageCapture related interfaces after adding trial token via script.");
 </script>