--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -43,16 +43,17 @@
 #include "nsServiceManagerUtils.h"
 #include "nsXULAppAPI.h"
 #include "nsWeakReference.h"
 #include "nsIScriptError.h"
 #include "nsIConsoleService.h"
 #include "nsJSEnvironment.h"
 #include "SandboxHal.h"
 #include "nsDebugImpl.h"
+#include "nsLayoutStylesheetCache.h"
 
 #include "History.h"
 #include "nsDocShellCID.h"
 #include "nsNetUtil.h"
 
 #include "base/message_loop.h"
 #include "base/process_util.h"
 #include "base/task.h"
@@ -903,21 +904,30 @@ ContentChild::RecvGarbageCollect()
 bool
 ContentChild::RecvCycleCollect()
 {
     nsJSContext::GarbageCollectNow(js::gcreason::DOM_IPC);
     nsJSContext::CycleCollectNow();
     return true;
 }
 
+static void
+PreloadSlowThings()
+{
+    // This fetches and creates all the built-in stylesheets.
+    nsLayoutStylesheetCache::UserContentSheet();
+}
+
 bool
 ContentChild::RecvAppInfo(const nsCString& version, const nsCString& buildID)
 {
     mAppInfo.version.Assign(version);
     mAppInfo.buildID.Assign(buildID);
+
+    PreloadSlowThings();
     return true;
 }
 
 bool
 ContentChild::RecvSetID(const PRUint64 &id)
 {
     if (mID != PRUint64(-1)) {
         NS_WARNING("Setting content child's ID twice?");