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

extensions/browser/process_manager.cc

Index: extensions/browser/process_manager.cc
diff --git a/extensions/browser/process_manager.cc b/extensions/browser/process_manager.cc
index 1b6a45a2e65584557d1e78121f1236c45def0028..575d855f3e3a79517fdd5ab9aaffca562cfa0764 100644
--- a/extensions/browser/process_manager.cc
+++ b/extensions/browser/process_manager.cc
@@ -338,7 +338,7 @@ ExtensionHost* ProcessManager::GetBackgroundHostForExtension(
     if (host->extension_id() == extension_id)
       return host;
   }
-  return NULL;
+  return nullptr;
 }
 
 std::set<RenderViewHost*> ProcessManager::GetRenderViewHostsForExtension(
@@ -363,7 +363,7 @@ std::set<RenderViewHost*> ProcessManager::GetRenderViewHostsForExtension(
 const Extension* ProcessManager::GetExtensionForRenderViewHost(
     RenderViewHost* render_view_host) {
   if (!render_view_host->GetSiteInstance())
-    return NULL;
+    return nullptr;
 
   return extension_registry_->enabled_extensions().GetByID(
       GetExtensionID(render_view_host));