Fix unprivileged user namespace regression

chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc

Index: chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc
diff --git a/chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc b/chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc
index b7cc45a8b536650f06a1eaa3352356793256857f..8e3d85ea7b9a3b72c0b914921b804709014e5b32 100644
--- a/chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc
+++ b/chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc
@@ -4,6 +4,14 @@
 
 #include "chrome/browser/ui/views/chrome_browser_main_extra_parts_views.h"
 
+#if defined(OS_LINUX)

[Tom (Use chromium acct), 2017/02/19 19:16:06]

Move ifdef'ed includes to the bottom

[Kevin Cernekee, 2017/02/19 19:33:46]

Done.

+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+
+#include <utility>
+
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/ui/views/chrome_constrained_window_views_client.h"
 #include "chrome/browser/ui/views/chrome_views_delegate.h"
@@ -77,6 +85,12 @@ void ChromeBrowserMainExtraPartsViews::PreProfileInit() {
   if (geteuid() != 0)
     return;
 
+  // Allow running inside an unprivileged user namespace. In that case, /

[Tom (Use chromium acct), 2017/02/19 19:16:06]

remove / ?

[Kevin Cernekee, 2017/02/19 19:33:46]

I changed it to "the root directory" to make the comment easier to follow.

+  // will be owned by an unmapped UID and GID.
+  struct stat st;
+  if (stat("/", &st) == 0 && st.st_uid != 0)
+    return;
+
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kNoSandbox))