Initialize NSS in the PPAPI process for ClearKey CDM.

crypto/nss_util.h

Index: crypto/nss_util.h
diff --git a/crypto/nss_util.h b/crypto/nss_util.h
index 9e09d6db47eb390c2246ed2f3c81d13f3820bab8..25043f973b226445da2e8d46ba7eb9782956ba7b 100644
--- a/crypto/nss_util.h
+++ b/crypto/nss_util.h
@@ -36,6 +36,16 @@ CRYPTO_EXPORT void EarlySetupForNSSInit();
 // thread-safe, and NSPR will only ever be initialized once.
 CRYPTO_EXPORT void EnsureNSPRInit();
 
+// Initialize NSS safely for strict sandboxing.  This function makes sure that
+// NSS is initialized safely and will have proper entropy in a restricted,
+// sandboxed environment.

[wtc, 2012/11/21 00:28:21]

Why do you call this "WarmUp" as opposed to "Init"?

It's not clear what you meant by "safely". The second paragraph
seems to say this means not loading any security modules,
but still doesn't give a direct definition of "safely".
I only fully understand what "safely" means after reading
the .cc file.

+//
+// As a defense in depth measure, this function should be called in a sandboxed
+// environment to make sure NSS will not load security modules that could
+// expose private data and keys.  Make sure to get an LGTM from Security
+// if you use this.

[wtc, 2012/11/21 00:28:21]

"Make sure to get an LGTM from Security if you use this"
isn't clear. I guess "Security" means the Chrome Security
Team?

+CRYPTO_EXPORT void WarmUpNSSSafely();
+
 // Initialize NSS if it isn't already initialized.  This must be called before
 // any other NSS functions.  This function is thread-safe, and NSS will only
 // ever be initialized once.
@@ -58,7 +68,7 @@ CRYPTO_EXPORT void EnsureNSSInit();
 // WARNING: Use this with caution.
 CRYPTO_EXPORT void ForceNSSNoDBInit();
 
-// This methods is used to disable checks in NSS when used in a forked process.
+// This method is used to disable checks in NSS when used in a forked process.
 // NSS checks whether it is running a forked process to avoid problems when
 // using user security modules in a forked process.  However if we are sure
 // there are no modules loaded before the process is forked then there is no