Initialize NSS in the PPAPI process for ClearKey CDM.

crypto/nss_util.cc

Index: crypto/nss_util.cc
diff --git a/crypto/nss_util.cc b/crypto/nss_util.cc
index 9933d30631671ebda919bc00cedc45ed25cbf13e..1be7efd7c8d1bc068e46d27824280e14f8bc34b5 100644
--- a/crypto/nss_util.cc
+++ b/crypto/nss_util.cc
@@ -650,6 +650,15 @@ void EnsureNSPRInit() {
   g_nspr_singleton.Get();
 }
 
+void WarmUpNSSSafely() {
+  // The Linux SUID sandbox would prevent opening user security modules anyway,
+  // but it's more correct to tell NSS to not do it.
+  // Loading user security modules would have security implications.
+  crypto::ForceNSSNoDBInit();
+  // Initialize NSS.
+  crypto::EnsureNSSInit();
+}
+
 void EnsureNSSInit() {
   // Initializing SSL causes us to do blocking IO.
   // Temporarily allow it until we fix