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

extensions/common/manifest_handlers/sandboxed_page_info.cc

Index: extensions/common/manifest_handlers/sandboxed_page_info.cc
diff --git a/extensions/common/manifest_handlers/sandboxed_page_info.cc b/extensions/common/manifest_handlers/sandboxed_page_info.cc
index 2471e93467d7699f429e37322dd4ec8a1c15bf99..3c8930e394adb5994164a04cd07362b88dc30101 100644
--- a/extensions/common/manifest_handlers/sandboxed_page_info.cc
+++ b/extensions/common/manifest_handlers/sandboxed_page_info.cc
@@ -64,7 +64,7 @@ SandboxedPageHandler::~SandboxedPageHandler() {
 bool SandboxedPageHandler::Parse(Extension* extension, base::string16* error) {
   scoped_ptr<SandboxedPageInfo> sandboxed_info(new SandboxedPageInfo);
 
-  const base::ListValue* list_value = NULL;
+  const base::ListValue* list_value = nullptr;
   if (!extension->manifest()->GetList(keys::kSandboxedPages, &list_value)) {
     *error = base::ASCIIToUTF16(errors::kInvalidSandboxedPagesList);
     return false;