Implement a poor man's PostAfterStartupTask() function.

content/browser/appcache/appcache_update_job.cc

Index: content/browser/appcache/appcache_update_job.cc
diff --git a/content/browser/appcache/appcache_update_job.cc b/content/browser/appcache/appcache_update_job.cc
index 4848c9a5f15019ae07ff5a5c0dc7d26e7239e3b0..66d2da804c8336f25faf013c21340201a22811c9 100644
--- a/content/browser/appcache/appcache_update_job.cc
+++ b/content/browser/appcache/appcache_update_job.cc
@@ -9,10 +9,12 @@
 #include "base/compiler_specific.h"
 #include "base/message_loop/message_loop.h"
 #include "base/profiler/scoped_tracker.h"
+#include "base/rand_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "content/browser/appcache/appcache_group.h"
 #include "content/browser/appcache/appcache_histograms.h"
+#include "content/public/browser/browser_main_runner.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
@@ -371,7 +373,8 @@ AppCacheUpdateJob::AppCacheUpdateJob(AppCacheServiceImpl* service,
       manifest_fetcher_(NULL),
       manifest_has_valid_mime_type_(false),
       stored_state_(UNSTORED),
-      storage_(service->storage()) {
+      storage_(service->storage()),
+      weak_factory_(this) {
     service_->AddObserver(this);
 }
 
@@ -451,6 +454,18 @@ void AppCacheUpdateJob::StartUpdate(AppCacheHost* host,
                               is_new_pending_master_entry);
   }
 
+  DelayableStart();
+}
+
+void AppCacheUpdateJob::DelayableStart() {
+  if (IsBrowserStartingUp()) {
+    // Defer running update jobs till after startup.
+    delayed_start_timer_.Start(
+        FROM_HERE, base::TimeDelta::FromSeconds(base::RandInt(5, 15)),

[cmumford, 2015/02/26 23:47:45]

Constants for 5 & 15?

Also (I don't know RandInt well), but do we need to see the random number
generator to avoid getting the same value at startup?

+        base::Bind(&AppCacheUpdateJob::DelayableStart,
+                   weak_factory_.GetWeakPtr()));
+    return;
+  }
   FetchManifest(true);
 }