[webcrypto] Reject PBKDF2 when iterations==0.

BUG=534947

Review URL: https://codereview.chromium.org/1381333002

Cr-Commit-Position: refs/heads/master@{#352430}
diff --git a/components/webcrypto/status.cc b/components/webcrypto/status.cc
index 54efffe82d..4747a7f0 100644
--- a/components/webcrypto/status.cc
+++ b/components/webcrypto/status.cc
@@ -351,6 +351,11 @@
       "No length was specified for the PBKDF2 Derive Bits operation.");
 }
 
+Status Status::ErrorPbkdf2Iterations0() {
+  return Status(blink::WebCryptoErrorTypeOperation,
+                "PBKDF2 requires iterations > 0");
+}
+
 Status::Status(blink::WebCryptoErrorType error_type,
                const std::string& error_details_utf8)
     : type_(TYPE_ERROR),