Run the later parts of startup as UI thread tasks

content/public/app/content_main_delegate.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_APP_CONTENT_MAIN_DELEGATE_H_
 #define CONTENT_PUBLIC_APP_CONTENT_MAIN_DELEGATE_H_
 
 #include <string>
 
 #include "build/build_config.h"
 #include "content/common/content_export.h"
+#include "content/public/common/startup_task_runner.h"
 
 namespace content {
 
 class ContentBrowserClient;
 class ContentPluginClient;
 class ContentRendererClient;
 class ContentUtilityClient;
 class ZygoteForkDelegate;
 struct MainFunctionParams;
 
 class CONTENT_EXPORT ContentMainDelegate {
  public:
+  ContentMainDelegate() {}
   virtual ~ContentMainDelegate() {}
 
   // Tells the embedder that the absolute basic startup has been done, i.e.
   // it's now safe to create singletons and check the command line. Return true
   // if the process should exit afterwards, and if so, |exit_code| should be
   // set. This is the place for embedder to do the things that must happen at
   // the start. Most of its startup code should be in the methods below.
   virtual bool BasicStartupComplete(int* exit_code);
 
   // This is where the embedder puts all of its startup code that needs to run
   // before the sandbox is engaged.
   virtual void PreSandboxStartup() {}
 
   // This is where the embedder can add startup code to run after the sandbox
   // has been initialized.
   virtual void SandboxInitialized(const std::string& process_type) {}
 
   // Asks the embedder to start a process. Return -1 for the default behavior.
   virtual int RunProcess(
       const std::string& process_type,
       const MainFunctionParams& main_function_params);
 
   // Called right before the process exits.
   virtual void ProcessExiting(const std::string& process_type) {}
 
+  // Call with true to allow the creation of a sequence of UI thread tasks to
+  // initialize the content layer. If not called, or called with false, content
+  // layer initialization must be completed in a single UI task.
+  // If called with true it is an implementation choice whether initialization
+  // requires multiple UI thread tasks.
+  virtual void EnableIncrementalStartup(bool enable) {};
+
+  // Set an observer to inform higher layers of startup progress
+  virtual void SetStartupObserver(
+      scoped_ptr<StartupTaskRunner::Observer> observer);
+
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   // Returns true if the process registers with the system monitor, so that we
   // can allocate an IO port for it before the sandbox is initialized. Embedders
   // are called only for process types that content doesn't know about.
   virtual bool ProcessRegistersWithSystemProcess(
       const std::string& process_type);
 
   // Used to determine if we should send the mach port to the parent process or
   // not. The embedder usually sends it for all child processes, use this to
   // override this behavior.
@@ skipping 16 matching lines @@
  protected:
   friend class ContentClientInitializer;
 
   // Called once per relevant process type to allow the embedder to customize
   // content. If an embedder wants the default (empty) implementation, don't
   // override this.
   virtual ContentBrowserClient* CreateContentBrowserClient();
   virtual ContentPluginClient* CreateContentPluginClient();
   virtual ContentRendererClient* CreateContentRendererClient();
   virtual ContentUtilityClient* CreateContentUtilityClient();
+
+  StartupTaskRunner::Observer* GetStartupObserver();
+
+ private:
+  scoped_ptr<StartupTaskRunner::Observer> startup_observer_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_APP_CONTENT_MAIN_DELEGATE_H_