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

content/child/webcrypto/webcrypto_impl.cc

Index: content/child/webcrypto/webcrypto_impl.cc
diff --git a/content/child/webcrypto/webcrypto_impl.cc b/content/child/webcrypto/webcrypto_impl.cc
index 04e031bf0bd95eaa971f7c19656ed8df3b083513..9d3897428bc302baf353767e0aa81ab9ceac26d9 100644
--- a/content/child/webcrypto/webcrypto_impl.cc
+++ b/content/child/webcrypto/webcrypto_impl.cc
@@ -552,12 +552,15 @@ void DoUnwrapKey(scoped_ptr<UnwrapKeyState> 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,