[webcrypto] Check for empty key usages *after* key creation rather than before, to match the spec's…

components/webcrypto/algorithms/hkdf.cc

Index: components/webcrypto/algorithms/hkdf.cc
diff --git a/components/webcrypto/algorithms/hkdf.cc b/components/webcrypto/algorithms/hkdf.cc
index bc10c35bc8a80f15f01011c0d8ef58f2e97a22d5..6b22d248989e80e826fef5170d1a37f8f05d57e6 100644
--- a/components/webcrypto/algorithms/hkdf.cc
+++ b/components/webcrypto/algorithms/hkdf.cc
@@ -29,19 +29,29 @@ class HkdfImplementation : public AlgorithmImplementation {
  public:
   HkdfImplementation() {}
 
-  Status VerifyKeyUsagesBeforeImportKey(
-      blink::WebCryptoKeyFormat format,
-      blink::WebCryptoKeyUsageMask usages) const override {
-    if (format != blink::WebCryptoKeyFormatRaw)
-      return Status::ErrorUnsupportedImportKeyFormat();
-    return CheckSecretKeyCreationUsages(kValidUsages, usages);
+  Status ImportKey(blink::WebCryptoKeyFormat format,
+                   const CryptoData& key_data,
+                   const blink::WebCryptoAlgorithm& algorithm,
+                   bool extractable,
+                   blink::WebCryptoKeyUsageMask usages,
+                   blink::WebCryptoKey* key) const override {
+    switch (format) {
+      case blink::WebCryptoKeyFormatRaw:
+        return ImportKeyRaw(key_data, algorithm, extractable, usages, key);
+      default:
+        return Status::ErrorUnsupportedImportKeyFormat();
+    }
   }
 
   Status ImportKeyRaw(const CryptoData& key_data,
                       const blink::WebCryptoAlgorithm& algorithm,
                       bool extractable,
                       blink::WebCryptoKeyUsageMask usages,
-                      blink::WebCryptoKey* key) const override {
+                      blink::WebCryptoKey* key) const {
+    Status status = CheckKeyCreationUsages(kValidUsages, usages);
+    if (status.IsError())
+      return status;
+
     return CreateWebCryptoSecretKey(
         key_data, blink::WebCryptoKeyAlgorithm::createWithoutParams(
                       blink::WebCryptoAlgorithmIdHkdf),