chromeos: Block system suspend while uploading files to Drive

content/public/browser/power_save_blocker.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_BROWSER_POWER_SAVE_BLOCKER_H_
-#define CONTENT_BROWSER_POWER_SAVE_BLOCKER_H_
+#ifndef CONTENT_PUBLIC_BROWSER_POWER_SAVE_BLOCKER_H_
+#define CONTENT_PUBLIC_BROWSER_POWER_SAVE_BLOCKER_H_
 
 #include <string>
-#include <vector>
 
 #include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
 // A RAII-style class to block the system from entering low-power (sleep) mode.
 // This class is thread-safe; it may be constructed and deleted on any thread.
 class CONTENT_EXPORT PowerSaveBlocker {
  public:
   enum PowerSaveBlockerType {
     // Prevent the application from being suspended. On some platforms, apps may
     // be suspended when they are not visible to the user. This type of block
     // requests that the app continue to run in that case, and on all platforms
     // prevents the system from sleeping.
     // Example use cases: downloading a file, playing audio.
     kPowerSaveBlockPreventAppSuspension,
 
     // Prevent the display from going to sleep. This also has the side effect of
     // preventing the system from sleeping, but does not necessarily prevent the
     // app from being suspended on some platforms if the user hides it.
     // Example use case: playing video.
     kPowerSaveBlockPreventDisplaySleep,
   };
 
+  virtual ~PowerSaveBlocker() = 0;
+
   // Pass in the type of power save blocking desired. If multiple types of
   // blocking are desired, instantiate one PowerSaveBlocker for each type.
   // |reason| may be provided to the underlying system APIs on some platforms.
-  PowerSaveBlocker(PowerSaveBlockerType type, const std::string& reason);
-  ~PowerSaveBlocker();
-
- private:
-  class Delegate;
-
-  // Implementations of this class may need a second object with different
-  // lifetime than the RAII container, or additional storage. This member is
-  // here for that purpose. If not used, just define the class as an empty
-  // RefCounted (or RefCountedThreadSafe) like so to make it compile:
-  // class PowerSaveBlocker::Delegate
-  //     : public base::RefCounted<PowerSaveBlocker::Delegate> {
-  //  private:
-  //   friend class base::RefCounted<Delegate>;
-  //   ~Delegate() {}
-  // };
-  scoped_refptr<Delegate> delegate_;
-
-  DISALLOW_COPY_AND_ASSIGN(PowerSaveBlocker);
+  static scoped_ptr<PowerSaveBlocker> Create(PowerSaveBlockerType type,
+                                             const std::string& reason);
 };
 
 }  // namespace content
 
-#endif  // CONTENT_BROWSER_POWER_SAVE_BLOCKER_H_
+#endif  // CONTENT_PUBLIC_BROWSER_POWER_SAVE_BLOCKER_H_