Decoupling visibility states from webcontent, adding visibility management in ResourceManager

athena/resource_manager/public/resource_manager.h

 // Copyright 2014 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 ATHENA_RESOURCE_MANAGER_PUBLIC_RESOURCE_MANAGER_H_
 #define ATHENA_RESOURCE_MANAGER_PUBLIC_RESOURCE_MANAGER_H_
 
 #include "athena/athena_export.h"
 #include "athena/resource_manager/memory_pressure_notifier.h"
 #include "base/basictypes.h"
@@ skipping 14 matching lines @@
   ResourceManager();
   virtual ~ResourceManager();
 
   // Unit tests can simulate MemoryPressure changes with this call.
   // Note: Even though the default unit test ResourceManagerDelegte
   // implementation ensures that the MemoryPressure event will not go off,
   // this call will also explicitly stop the MemoryPressureNotifier.
   virtual void SetMemoryPressureAndStopMonitoring(
       MemoryPressureObserver::MemoryPressure pressure) = 0;
 
+  // Suspend the resource manager temporarily if |pause| is set. This can be
+  // called before e.g. re-arranging the order of activities. Once called with
+  // |pause| == false any queued operations will be performed and the resource
+  // manager will continue its work.
+  virtual void Pause(bool pause) = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ResourceManager);
 };
 
+// Use this scoped object to pause/restart the resource manager.
+class ScopedPauseResourceManager {
+ public:
+  ScopedPauseResourceManager() {
+    ResourceManager::Get()->Pause(true);
+  }
+  ~ScopedPauseResourceManager() {
+    ResourceManager::Get()->Pause(false);
+  }
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScopedPauseResourceManager);
+};
+
 }  // namespace athena
 
 #endif  // ATHENA_RESOURCE_MANAGER_PUBLIC_RESOURCE_MANAGER_H_