Use command line to signal whether a child process was passed V8 snapshot files via file descriptor

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 7e5471aa886ad8ac40d4cdc14b82f28c240d7c88..545f0c95368467f61e0df96abc017c8fa16d48fb 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -397,6 +397,14 @@ const char kEnablePushMessagingHasPermission[] =
 // Set options to cache V8 data. (off, preparse data, or code)
 const char kV8CacheOptions[] = "v8-cache-options";
 
+// Signals that the V8 natives file has been transfered to the child process
+// by a file descriptor.
+const char kV8NativesPassedByFD[] = "v8-natives-passed-by-fd";
+
+// Signals that the V8 startup snapshot file has been transfered to the child
+// process by a file descriptor.
+const char kV8SnapshotPassedByFD[] = "v8-snapshot-passed-by-fd";

[James Cook, 2015/04/09 16:27:08]

Is it ever valid to pass just one of these files and not the other?  If they
always go together consider just using a single switch -- it'll make it less
likely for someone to miss one, or pass the same one twice.

[rmcilroy, 2015/04/09 22:14:59]

Currently we will always pass both files, however there is a change in-progress
to generate the snapshot file on-demand, which would mean we would pass the
natives file, but not the snapshot file - this is the reason I made this two
separate switches.

+
 // Enables the CSS multicol implementation that uses the regions implementation.
 const char kEnableRegionBasedColumns[] =
     "enable-region-based-columns";