PPAPI: Make GLES2 calls resilient to bad/dead resources.

ppapi/shared_impl/proxy_lock.h

Index: ppapi/shared_impl/proxy_lock.h
diff --git a/ppapi/shared_impl/proxy_lock.h b/ppapi/shared_impl/proxy_lock.h
index 9a81a13baa1366c6003bfc9ebfa56e19a5b02675..f6dea318417093e9b08754c565e253e6ebb10298 100644
--- a/ppapi/shared_impl/proxy_lock.h
+++ b/ppapi/shared_impl/proxy_lock.h
@@ -50,6 +50,11 @@ class PPAPI_SHARED_EXPORT ProxyLock {
   // Assert that the lock is owned by the current thread (in the plugin
   // process). Does nothing when running in-process (or in the host process).
   static void AssertAcquired();
+  static void AssertAcquiredDebugOnly() {
+#ifndef NDEBUG
+    AssertAcquired();
+#endif
+  }
 
   // We have some unit tests where one thread pretends to be the host and one
   // pretends to be the plugin. This allows the lock to do nothing on only one