libchrome: Several upstreamable fixes from libchrome

base/files/file_util_linux.cc

Index: base/files/file_util_linux.cc
diff --git a/base/files/file_util_linux.cc b/base/files/file_util_linux.cc
index b230fd96484c7d8e75f408edc912019d60ffb728..b0c6e0328507fde90d4e09e7d24c4b1089216159 100644
--- a/base/files/file_util_linux.cc
+++ b/base/files/file_util_linux.cc
@@ -6,6 +6,7 @@
 
 #include <errno.h>
 #include <linux/magic.h>
+#include <stdint.h>
 #include <sys/vfs.h>
 
 #include "base/files/file_path.h"
@@ -23,7 +24,10 @@ bool GetFileSystemType(const FilePath& path, FileSystemType* type) {
 
   // Not all possible |statfs_buf.f_type| values are in linux/magic.h.
   // Missing values are copied from the statfs man page.
-  switch (statfs_buf.f_type) {
+  // In some platforms, |statfs_buf.f_type| is declared as signed, but some of
+  // the values will overflow it, causing narrowing warnings. Cast to the
+  // largest possible unsigned integer type to avoid it.
+  switch (static_cast<uintmax_t>(statfs_buf.f_type)) {
     case 0:
       *type = FILE_SYSTEM_0;
       break;