Refactor the interface for generating keys.

content/child/webcrypto/algorithm_implementation.h

Index: content/child/webcrypto/algorithm_implementation.h
diff --git a/content/child/webcrypto/algorithm_implementation.h b/content/child/webcrypto/algorithm_implementation.h
index ac32413bcb83c4658eba7366fc61f2a6245b1690..aee363b50fd7ae200814597840fb1b2f7f6d88e6 100644
--- a/content/child/webcrypto/algorithm_implementation.h
+++ b/content/child/webcrypto/algorithm_implementation.h
@@ -71,32 +71,17 @@ class AlgorithmImplementation {
                         const CryptoData& data,
                         std::vector<uint8_t>* buffer) const;
 
-  // VerifyKeyUsagesBeforeGenerateKey() must be called prior to
-  // GenerateSecretKey() to validate the requested key usages.
-  virtual Status VerifyKeyUsagesBeforeGenerateKey(
-      blink::WebCryptoKeyUsageMask usage_mask) const;
-
   // This method corresponds to Web Crypto's crypto.subtle.generateKey().
-  virtual Status GenerateSecretKey(const blink::WebCryptoAlgorithm& algorithm,
-                                   bool extractable,
-                                   blink::WebCryptoKeyUsageMask usage_mask,
-                                   blink::WebCryptoKey* key) const;
-
-  // VerifyKeyUsagesBeforeGenerateKeyPair() must be called prior to
-  // GenerateKeyPair() to validate the requested key usages.
-  virtual Status VerifyKeyUsagesBeforeGenerateKeyPair(
-      blink::WebCryptoKeyUsageMask combined_usage_mask,
-      blink::WebCryptoKeyUsageMask* public_usage_mask,
-      blink::WebCryptoKeyUsageMask* private_usage_mask) const;
-
-  // This method corresponds to Web Crypto's crypto.subtle.generateKey().
-  virtual Status GenerateKeyPair(
-      const blink::WebCryptoAlgorithm& algorithm,
-      bool extractable,
-      blink::WebCryptoKeyUsageMask public_usage_mask,
-      blink::WebCryptoKeyUsageMask private_usage_mask,
-      blink::WebCryptoKey* public_key,
-      blink::WebCryptoKey* private_key) const;
+  // In the case of a symmetric algorithm, the secret key should be written to
+  // |*private_key|.
+  //
+  // Implementations MUST verify |usage_mask| and return an error if it is not
+  // appropriate.
+  virtual Status GenerateKey(const blink::WebCryptoAlgorithm& algorithm,
+                             bool extractable,
+                             blink::WebCryptoKeyUsageMask usage_mask,
+                             blink::WebCryptoKey* public_key,
+                             blink::WebCryptoKey* private_key) const;
 
   // -----------------------------------------------
   // Key import