[C++11 Allowed Features] Declares a type-safe null pointer converting from NULL to  nullptr in src/cc [part-2]

BUG =

Review URL: https://codereview.chromium.org/643583003

Cr-Commit-Position: refs/heads/master@{#299106}
diff --git a/cc/debug/invalidation_benchmark.cc b/cc/debug/invalidation_benchmark.cc
index f063fe71d..87d2edd 100644
--- a/cc/debug/invalidation_benchmark.cc
+++ b/cc/debug/invalidation_benchmark.cc
@@ -28,7 +28,7 @@
     scoped_ptr<base::Value> value,
     const MicroBenchmark::DoneCallback& callback)
     : MicroBenchmark(callback), seed_(0) {
-  base::DictionaryValue* settings = NULL;
+  base::DictionaryValue* settings = nullptr;
   value->GetAsDictionary(&settings);
   if (!settings)
     return;
@@ -111,7 +111,7 @@
 }
 
 bool InvalidationBenchmark::ProcessMessage(scoped_ptr<base::Value> value) {
-  base::DictionaryValue* message = NULL;
+  base::DictionaryValue* message = nullptr;
   value->GetAsDictionary(&message);
   if (!message)
     return false;