Webcrypto: add layout tests for HKDF algorithm

LayoutTests/crypto/subtle/hkdf-deriveKey-expected.txt

Index: LayoutTests/crypto/subtle/hkdf-deriveKey-expected.txt
diff --git a/LayoutTests/crypto/subtle/hkdf-deriveKey-expected.txt b/LayoutTests/crypto/subtle/hkdf-deriveKey-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..f58843627cb53a0f4f1705564f7f986fa5afa501
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+++ b/LayoutTests/crypto/subtle/hkdf-deriveKey-expected.txt
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+Test that keys can be derived from an HKDF key
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS derivedKey.type is "secret"
+PASS typeof derivedKey.extractable is 'boolean'
+PASS derivedKey.extractable is true
+PASS derivedKey.algorithm.name is "AES-GCM"
+PASS derivedKey.usages.join(',') is "encrypt"
+
+Try to derive an HKDF key...
+error is: TypeError: No length was specified for the HKDF Derive Bits operation.
+PASS emptyKey.type is "secret"
+PASS typeof emptyKey.extractable is 'boolean'
+PASS emptyKey.extractable is true
+PASS emptyKey.algorithm.name is "HKDF"
+PASS emptyKey.usages.join(',') is "deriveKey"
+PASS derivedKey.type is "secret"
+PASS typeof derivedKey.extractable is 'boolean'
+PASS derivedKey.extractable is true
+PASS derivedKey.algorithm.name is "AES-GCM"
+PASS derivedKey.usages.join(',') is "encrypt"
+PASS successfullyParsed is true
+
+TEST COMPLETE
+