Switch to standard integer types in extensions/.

BUG=138542
[email protected]

Review URL: https://codereview.chromium.org/1543053002

Cr-Commit-Position: refs/heads/master@{#366716}
diff --git a/extensions/renderer/v8_helpers.h b/extensions/renderer/v8_helpers.h
index 0c9a47c..2a6fa9c 100644
--- a/extensions/renderer/v8_helpers.h
+++ b/extensions/renderer/v8_helpers.h
@@ -5,6 +5,7 @@
 #ifndef EXTENSIONS_RENDERER_V8_HELPERS_H_
 #define EXTENSIONS_RENDERER_V8_HELPERS_H_
 
+#include <stdint.h>
 #include <string.h>
 
 #include "base/strings/string_number_conversions.h"