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

extensions/common/update_manifest.cc

Index: extensions/common/update_manifest.cc
diff --git a/extensions/common/update_manifest.cc b/extensions/common/update_manifest.cc
index 26d794f11f4ec9f25262169d98082473399ad41e..4ce1aab8d21198e172479f5d231b50a49c96074d 100644
--- a/extensions/common/update_manifest.cc
+++ b/extensions/common/update_manifest.cc
@@ -60,7 +60,7 @@ static bool TagNameEquals(const xmlNode* node, const char* expected_name,
 static std::vector<xmlNode*> GetChildren(xmlNode* root, xmlNs* xml_namespace,
                                          const char* name) {
   std::vector<xmlNode*> result;
-  for (xmlNode* child = root->children; child != NULL; child = child->next) {
+  for (xmlNode* child = root->children; child != nullptr; child = child->next) {
     if (!TagNameEquals(child, name, xml_namespace)) {
       continue;
     }
@@ -72,7 +72,7 @@ static std::vector<xmlNode*> GetChildren(xmlNode* root, xmlNs* xml_namespace,
 // Returns the value of a named attribute, or the empty string.
 static std::string GetAttribute(xmlNode* node, const char* attribute_name) {
   const xmlChar* name = reinterpret_cast<const xmlChar*>(attribute_name);
-  for (xmlAttr* attr = node->properties; attr != NULL; attr = attr->next) {
+  for (xmlAttr* attr = node->properties; attr != nullptr; attr = attr->next) {
     if (!xmlStrcmp(attr->name, name) && attr->children &&
         attr->children->content) {
       return std::string(reinterpret_cast<const char*>(
@@ -113,12 +113,12 @@ class ScopedXmlDocument {
 // NULL if there isn't one with that href.
 static xmlNs* GetNamespace(xmlNode* node, const char* expected_href) {
   const xmlChar* href = reinterpret_cast<const xmlChar*>(expected_href);
-  for (xmlNs* ns = node->ns; ns != NULL; ns = ns->next) {
+  for (xmlNs* ns = node->ns; ns != nullptr; ns = ns->next) {
     if (ns->href && !xmlStrcmp(ns->href, href)) {
       return ns;
     }
   }
-  return NULL;
+  return nullptr;
 }