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

extensions/shell/browser/shell_browser_context.cc

Index: extensions/shell/browser/shell_browser_context.cc
diff --git a/extensions/shell/browser/shell_browser_context.cc b/extensions/shell/browser/shell_browser_context.cc
index 33a08e3c99815994cc038c1c08ffe963f625cd6e..f1f00d8c6411d7f172e3af8940563c99176c4d9d 100644
--- a/extensions/shell/browser/shell_browser_context.cc
+++ b/extensions/shell/browser/shell_browser_context.cc
@@ -12,7 +12,7 @@ namespace extensions {
 // Create a normal recording browser context. If we used an incognito context
 // then app_shell would also have to create a normal context and manage both.
 ShellBrowserContext::ShellBrowserContext()
-    : content::ShellBrowserContext(false, NULL),
+    : content::ShellBrowserContext(false, nullptr),
       storage_policy_(new ShellSpecialStoragePolicy) {
 }