Backed out 7 changesets (bug 1627075) for causing @nsZipArchive crashes CLOSED TREE

Backed out changeset 9705b2759d45 (bug 1627075)
Backed out changeset 699212a443c3 (bug 1627075)
Backed out changeset 7ae4df10749c (bug 1627075)
Backed out changeset ece9a4223349 (bug 1627075)
Backed out changeset 6c4eedaa0d04 (bug 1627075)
Backed out changeset f5106898239f (bug 1627075)
Backed out changeset b6029c7c0016 (bug 1627075)

js/xpconnect/loader/mozJSSubScriptLoader.cpp

@@ -24,7 +24,6 @@
 
 #include "mozilla/ContentPrincipal.h"
 #include "mozilla/dom/ScriptLoader.h"
-#include "mozilla/Omnijar.h"
 #include "mozilla/ScriptPreloader.h"
 #include "mozilla/SystemPrincipal.h"
 #include "mozilla/scache/StartupCache.h"
@@ -249,10 +248,6 @@ bool mozJSSubScriptLoader::ReadScript(JS::MutableHandle<JSScript*> script,
                                       const char* uriStr, nsIIOService* serv,
                                       bool wantReturnValue,
                                       bool useCompilationScope) {
-  // We're going to cache the XDR encoded script data - suspend writes via the
-  // CacheAwareZipReader, otherwise we'll end up redundantly caching scripts.
-  AutoSuspendStartupCacheWrites suspendScache;
-
   // We create a channel and call SetContentType, to avoid expensive MIME type
   // lookups (bug 632490).
   nsCOMPtr<nsIChannel> chan;
@@ -455,15 +450,7 @@ nsresult mozJSSubScriptLoader::DoLoadSubScriptWithOptions(
   bool ignoreCache =
       options.ignoreCache || !isSystem || scheme.EqualsLiteral("blob");
 
-  // Since we are intending to cache these buffers in the script preloader
-  // already, caching them in the StartupCache tends to be redundant. This
-  // ought to be addressed, but as in bug 1627075 we extended the
-  // StartupCache to be multi-process, we just didn't want to propagate
-  // this problem into yet more processes, so we pretend the StartupCache
-  // doesn't exist if we're not the parent process.
-  StartupCache* cache = (ignoreCache || !XRE_IsParentProcess())
-                            ? nullptr
-                            : StartupCache::GetSingleton();
+  StartupCache* cache = ignoreCache ? nullptr : StartupCache::GetSingleton();
 
   nsAutoCString cachePath;
   SubscriptCachePath(cx, uri, targetObj, cachePath);