Improve LayoutTest output for Errors

LayoutTests/crypto/aes-kw-generateKey-parseAlgorithm-failures.html

Index: LayoutTests/crypto/aes-kw-generateKey-parseAlgorithm-failures.html
diff --git a/LayoutTests/crypto/aes-kw-generateKey-parseAlgorithm-failures.html b/LayoutTests/crypto/aes-kw-generateKey-parseAlgorithm-failures.html
index 9c17fada6e3c1dff36e8232720acb1d705217473..e35bbbeb3c2ab9ae175cb69a358bbfb6f1810064 100644
--- a/LayoutTests/crypto/aes-kw-generateKey-parseAlgorithm-failures.html
+++ b/LayoutTests/crypto/aes-kw-generateKey-parseAlgorithm-failures.html
@@ -16,18 +16,22 @@ extractable = true;
 keyUsages = ['wrapKey', 'unwrapKey'];
 
 Promise.resolve(null).then(function() {
+    debug("\ngenerateKey() without length...");
     return crypto.subtle.generateKey({ name: 'aes-kw' }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);
 
+    debug("\ngenerateKey() with a length of 70000...");
     return crypto.subtle.generateKey({ name: 'aes-kw', length: 70000 }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);
 
+    debug("\ngenerateKey() with a length of -3...");
     return crypto.subtle.generateKey({ name: 'aes-kw', length: -3 }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);
 
+    debug("\ngenerateKey() with length that is minus Infinity...");
     return crypto.subtle.generateKey({ name: 'aes-kw', length: -Infinity }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);