Raise an error when calling WebCrypto's deriveBits() for HKDF with

components/webcrypto/status.h

Index: components/webcrypto/status.h
diff --git a/components/webcrypto/status.h b/components/webcrypto/status.h
index 5933623e848d2f7bab70bca759e8597cbac74a5a..2c7dfa7b9c5c92b69b8c3ac8288b8507cc4dbb45 100644
--- a/components/webcrypto/status.h
+++ b/components/webcrypto/status.h
@@ -258,6 +258,9 @@ class Status {
   // The requested length for HKDF was too large.
   static Status ErrorHkdfLengthTooLong();
 
+  // The length to HKDF's deriveBits() was not a multiple of 8.
+  static Status ErrorHkdfLengthNotWholeByte();
+
   // No length parameter was provided for HKDF's Derive Bits operation.
   static Status ErrorHkdfDeriveBitsLengthNotSpecified();