Have each SandboxedProcessLauncherDelegate maintain a zygote.

chrome/browser/memory_details.cc

Index: chrome/browser/memory_details.cc
diff --git a/chrome/browser/memory_details.cc b/chrome/browser/memory_details.cc
index b53eb2dda5666a7548a3cfdf4fa98a1abee70ec6..ea551c73e61641df098446578e08d4430773be78 100644
--- a/chrome/browser/memory_details.cc
+++ b/chrome/browser/memory_details.cc
@@ -211,11 +211,6 @@ void MemoryDetails::CollectChildInfoOnIOThread(CollectionMode mode) {
 
 void MemoryDetails::CollectChildInfoOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
-  const pid_t zygote_pid = content::ZygoteHost::GetInstance()->GetPid();
-#endif
-
   ProcessData* const chrome_browser = ChromeBrowser();
 
   // First pass, collate the widgets by process ID.
@@ -367,7 +362,7 @@ void MemoryDetails::CollectChildInfoOnUIThread() {
     }
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
-    if (process.pid == zygote_pid) {
+    if (content::ZygoteHost::GetInstance()->IsZygotePid(process.pid)) {
       process.process_type = content::PROCESS_TYPE_ZYGOTE;
     }
 #endif