Improve LayoutTest output for Errors

LayoutTests/crypto/ecdsa-generateKey-parseAlgorithm-failures.html

Index: LayoutTests/crypto/ecdsa-generateKey-parseAlgorithm-failures.html
diff --git a/LayoutTests/crypto/ecdsa-generateKey-parseAlgorithm-failures.html b/LayoutTests/crypto/ecdsa-generateKey-parseAlgorithm-failures.html
index 6b65123a6d817c1761d6a964735457df5e239643..ef324fb1c03483f81d4b437b8915cbf1fc70a2e7 100644
--- a/LayoutTests/crypto/ecdsa-generateKey-parseAlgorithm-failures.html
+++ b/LayoutTests/crypto/ecdsa-generateKey-parseAlgorithm-failures.html
@@ -17,21 +17,25 @@ keyUsages = ['sign', 'verify'];
 
 Promise.resolve(null).then(function() {
     // Missing curve name.
+    debug("\ngenerateKey() without namedCurve...");
     return crypto.subtle.generateKey({name: 'ECDSA'}, extractable , keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);
 
     // Named curve is invalid (an integer when it should be a string).
+    debug("\ngenerateKey() with namedCurve that is an integer...");
     return crypto.subtle.generateKey({name: 'ECDSA', namedCurve: -1}, extractable , keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);
 
     // Named curve is unrecognized (lower case when it should be upper case)
+    debug("\ngenerateKey() with lower case namedCurve...");
     return crypto.subtle.generateKey({name: 'ECDSA', namedCurve: 'p-256'}, extractable , keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);
 
     // Named curve is unrecognized (contains some trailing characters).
+    debug("\ngenerateKey() with namedCurve that contains some trailing characters...");
     return crypto.subtle.generateKey({name: 'ECDSA', namedCurve: 'P-256aa'}, extractable , keyUsages);
 }).then(failAndFinishJSTest, function(result) {
     logError(result);