Pass both 32 and 64 bit snapshot and natives fds to child processes.

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index a8235c3385d328c78da00f783be8f4a31ded2936..37fd3b8d2dcb1189d99844d30b30d80d71f24d51 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -139,6 +139,16 @@ base::LazyInstance<ContentUtilityClient>
     g_empty_content_utility_client = LAZY_INSTANCE_INITIALIZER;
 #endif  // !OS_IOS && !CHROME_MULTIPLE_DLL_BROWSER
 
+#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+#if defined __LP64__
+#define kV8NativesDataDescriptor kV8NativesDataDescriptor64
+#define kV8SnapshotDataDescriptor kV8SnapshotDataDescriptor64
+#else
+#define kV8NativesDataDescriptor kV8NativesDataDescriptor32
+#define kV8SnapshotDataDescriptor kV8SnapshotDataDescriptor32
+#endif
+#endif
+
 #if defined(OS_POSIX) && !defined(OS_IOS)
 
 // Setup signal-handling state: resanitize most signals, ignore SIGPIPE.