Implement a poor man's PostAfterStartupTask() function.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 31959739147ca2cb4c74666050db4a9c7f1c45ef..6609c295e347b098120f87ca6bd3dbc1720d4b83 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -142,6 +142,15 @@ class CONTENT_EXPORT ContentBrowserClient {
   virtual BrowserMainParts* CreateBrowserMainParts(
       const MainFunctionParams& parameters);
 
+  // Allows the embedder to change the default behavior of
+  // BrowserThread::PostAfterStartupTask to better match whatever
+  // definition of "startup" the embedder has in mind.
+  // Note: see related BrowserThread.PostAfterStartupTask.
+  virtual void PostAfterStartupTask(
+      const tracked_objects::Location& from_here,
+      const scoped_refptr<base::TaskRunner>& task_runner,
+      const base::Closure& task);
+
   // If content creates the WebContentsView implementation, it will ask the
   // embedder to return an (optional) delegate to customize it. The view will
   // own the delegate.