Enable some parts of base that were previously disabled in base_untrusted

base/rand_util_nacl.cc

Index: base/rand_util_nacl.cc
diff --git a/base/rand_util_nacl.cc b/base/rand_util_nacl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..47450aaba68be254001da2f5e9d84e182b19ed76
--- /dev/null
+++ b/base/rand_util_nacl.cc
@@ -0,0 +1,53 @@
+// Copyright (c) 2012 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 "base/rand_util.h"
+
+#include "base/basictypes.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "native_client/src/untrusted/irt/irt.h"
+
+namespace {
+
+class NaclRandom {
+ public:
+  NaclRandom() {
+    size_t result = nacl_interface_query(NACL_IRT_RANDOM_v0_1,
+                                         &random_, sizeof(random_));
+    CHECK_EQ(result, sizeof(random_));
+  }
+
+  ~NaclRandom() {
+  }
+
+  void GetRandomBytes(char* buffer, uint32_t num_bytes) {
+    while (num_bytes > 0) {
+      size_t nread;
+      int error = random_.get_random_bytes(buffer, num_bytes, &nread);
+      CHECK_EQ(error, 0);
+      CHECK_LE(nread, num_bytes);
+      buffer += nread;
+      num_bytes -= nread;
+    }
+  }
+
+ private:
+  nacl_irt_random random_;
+};
+
+base::LazyInstance<NaclRandom>::Leaky g_nacl_random = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+namespace base {
+
+uint64 RandUint64() {
+  uint64 result;
+  g_nacl_random.Pointer()->GetRandomBytes(
+      reinterpret_cast<char*>(&result), sizeof(result));
+  return result;
+}
+
+}  // namespace base