Clean up Linux zygote creation code

content/browser/zygote_host/zygote_communication_linux.h

Index: content/browser/zygote_host/zygote_communication_linux.h
diff --git a/content/browser/zygote_host/zygote_communication_linux.h b/content/browser/zygote_host/zygote_communication_linux.h
index 32a2822b9f20b1d2979717b40e4ab8785c8f49b2..2b5340386c7d52aa5c277b195e84e69a7ad959f3 100644
--- a/content/browser/zygote_host/zygote_communication_linux.h
+++ b/content/browser/zygote_host/zygote_communication_linux.h
@@ -25,6 +25,9 @@ class Pickle;
 
 namespace content {
 
+// Handles interprocess communication with the Linux zygote process. The zygote
+// does not use standard Chrome IPC or mojo, see:
+// https://chromium.googlesource.com/chromium/src/+/master/docs/linux_sandbox_ipc.md
 class CONTENT_EXPORT ZygoteCommunication {
  public:
   ZygoteCommunication();