[webcrypto] Reject failed operations with a DOMException rather than null.

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

Index: LayoutTests/crypto/aes-cbc-generateKey-parseAlgorithm-failures.html
diff --git a/LayoutTests/crypto/aes-cbc-generateKey-parseAlgorithm-failures.html b/LayoutTests/crypto/aes-cbc-generateKey-parseAlgorithm-failures.html
index 8e1601bc3ff92d95f3987c0178df8a7288a333a7..ef0b91de105df66862982e4550f0765664494914 100644
--- a/LayoutTests/crypto/aes-cbc-generateKey-parseAlgorithm-failures.html
+++ b/LayoutTests/crypto/aes-cbc-generateKey-parseAlgorithm-failures.html
@@ -19,40 +19,33 @@ Promise.resolve(null).then(function() {
     // Invalid keyUsages
     return crypto.subtle.generateKey({ name: 'aes-cbc', length: 1024 }, extractable, -1);
 }).then(failAndFinishJSTest, function(result) {
-    error = result
-    shouldBeTypeError("error");
+    logError(result);
 
     // Invalid keyUsages
     return crypto.subtle.generateKey({ name: 'aes-cbc', length: 1024 }, extractable, null);
 }).then(failAndFinishJSTest, function(result) {
-    error = result
-    shouldBeTypeError("error");
+    logError(result);
 
     // Bad key usage "boo".
     return crypto.subtle.generateKey({ name: 'aes-cbc', length: 1024 }, extractable, ['boo']);
 }).then(failAndFinishJSTest, function(result) {
-    error = result;
-    shouldBeNull("error");
+    logError(result);
 
     return crypto.subtle.generateKey({ name: 'aes-cbc' }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
-    error = result;
-    shouldBeNull("error");
+    logError(result);
 
     return crypto.subtle.generateKey({ name: 'aes-cbc', length: 70000 }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
-    error = result;
-    shouldBeNull("error");
+    logError(result);
 
     return crypto.subtle.generateKey({ name: 'aes-cbc', length: -3 }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
-    error = result;
-    shouldBeNull("error");
+    logError(result);
 
     return crypto.subtle.generateKey({ name: 'aes-cbc', length: -Infinity }, extractable, keyUsages);
 }).then(failAndFinishJSTest, function(result) {
-    error = result;
-    shouldBeNull("error");
+    logError(result);
 }).then(finishJSTest, failAndFinishJSTest);
 
 </script>