Run clang-modernize -use-nullptr over src/extensions/.

extensions/browser/extension_function_registry.cc

 // Copyright 2014 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 "extensions/browser/extension_function_registry.h"
 
 #include "base/memory/singleton.h"
 #include "extensions/browser/extension_function.h"
 #include "extensions/browser/extensions_browser_client.h"
 
@@ skipping 28 matching lines @@
   } else {
     iter->second.factory_ = factory;
     return true;
   }
 }
 
 ExtensionFunction* ExtensionFunctionRegistry::NewFunction(
     const std::string& name) {
   FactoryMap::iterator iter = factories_.find(name);
   if (iter == factories_.end()) {
-    return NULL;
+    return nullptr;
   }
   ExtensionFunction* function = iter->second.factory_();
   function->set_name(name);
   function->set_histogram_value(iter->second.histogram_value_);
   return function;
 }
 
 ExtensionFunctionRegistry::FactoryEntry::FactoryEntry()
-    : factory_(0), histogram_value_(extensions::functions::UNKNOWN) {}
+    : factory_(nullptr), histogram_value_(extensions::functions::UNKNOWN) {
+}
 
 ExtensionFunctionRegistry::FactoryEntry::FactoryEntry(
     ExtensionFunctionFactory factory,
     extensions::functions::HistogramValue histogram_value)
     : factory_(factory), histogram_value_(histogram_value) {}