Implement a poor man's PostAfterStartupTask() function.

content/browser/browser_thread_impl.cc

Index: content/browser/browser_thread_impl.cc
diff --git a/content/browser/browser_thread_impl.cc b/content/browser/browser_thread_impl.cc
index a8ce1b0dcd510dea55cc7a95829e83bd116bd345..6b8043a09d98975d13457f19f167e0cbfe5f3bfa 100644
--- a/content/browser/browser_thread_impl.cc
+++ b/content/browser/browser_thread_impl.cc
@@ -15,6 +15,8 @@
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_restrictions.h"
 #include "content/public/browser/browser_thread_delegate.h"
+#include "content/public/browser/content_browser_client.h"
+#include "content/public/common/content_client.h"
 #include "net/disk_cache/simple/simple_backend_impl.h"
 
 #if defined(OS_ANDROID)
@@ -365,6 +367,15 @@ bool BrowserThread::PostBlockingPoolSequencedTask(
 }
 
 // static
+void BrowserThread::PostAfterStartupTask(
+      const tracked_objects::Location& from_here,
+      const scoped_refptr<base::TaskRunner>& task_runner,
+      const base::Closure& task) {
+  GetContentClient()->browser()->PostAfterStartupTask(
+      from_here, task_runner, task);
+}
+
+// static
 base::SequencedWorkerPool* BrowserThread::GetBlockingPool() {
   return g_globals.Get().blocking_pool.get();
 }