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

extensions/shell/browser/shell_content_browser_client.cc

Index: extensions/shell/browser/shell_content_browser_client.cc
diff --git a/extensions/shell/browser/shell_content_browser_client.cc b/extensions/shell/browser/shell_content_browser_client.cc
index 3fb07f552b308886092dfec8fbb62d90573ce4b0..72b14ae41afe3c93af9faea2e8d06bbeed9706fb 100644
--- a/extensions/shell/browser/shell_content_browser_client.cc
+++ b/extensions/shell/browser/shell_content_browser_client.cc
@@ -41,19 +41,20 @@ using content::BrowserThread;
 namespace extensions {
 namespace {
 
-ShellContentBrowserClient* g_instance = NULL;
+ShellContentBrowserClient* g_instance = nullptr;
 
 }  // namespace
 
 ShellContentBrowserClient::ShellContentBrowserClient(
     ShellBrowserMainDelegate* browser_main_delegate)
-    : browser_main_parts_(NULL), browser_main_delegate_(browser_main_delegate) {
+    : browser_main_parts_(nullptr),
+      browser_main_delegate_(browser_main_delegate) {
   DCHECK(!g_instance);
   g_instance = this;
 }
 
 ShellContentBrowserClient::~ShellContentBrowserClient() {
-  g_instance = NULL;
+  g_instance = nullptr;
 }
 
 // static
@@ -207,7 +208,7 @@ ShellContentBrowserClient::GetExternalBrowserPpapiHost(int plugin_process_id) {
     ++iter;
   }
 #endif
-  return NULL;
+  return nullptr;
 }
 
 void ShellContentBrowserClient::GetAdditionalAllowedSchemesForFileSystem(