[webcrypto] Fix a race in BlinkPlatformImpl::crypto(), by using eager initilization of WebCryptoImpl

content/child/webcrypto/webcrypto_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/webcrypto/webcrypto_impl.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 534 matching lines @@
                            state->usages,
                            &state->unwrapped_key);
 
   state->origin_thread->PostTask(
       FROM_HERE, base::Bind(DoUnwrapKeyReply, Passed(&passed_state)));
 }
 
 }  // namespace
 
 WebCryptoImpl::WebCryptoImpl() {
-  webcrypto::Init();
 }
 
 WebCryptoImpl::~WebCryptoImpl() {
 }
 
+void WebCryptoImpl::EnsureInit() {
+  webcrypto::Init();
+}
+
 void WebCryptoImpl::encrypt(const blink::WebCryptoAlgorithm& algorithm,
                             const blink::WebCryptoKey& key,
                             const unsigned char* data,
                             unsigned int data_size,
                             blink::WebCryptoResult result) {
   DCHECK(!algorithm.isNull());
 
   scoped_ptr<EncryptState> state(
       new EncryptState(algorithm, key, data, data_size, result));
   if (!CryptoThreadPool::PostTask(FROM_HERE,
@@ skipping 165 matching lines @@
       &key);
 }
 
 bool WebCryptoImpl::serializeKeyForClone(
     const blink::WebCryptoKey& key,
     blink::WebVector<unsigned char>& key_data) {
   return webcrypto::SerializeKeyForClone(key, &key_data);
 }
 
 }  // namespace content