[Offline Pages] Implement OfflinePageStorageManager.

components/offline_pages/offline_page_model.h

Index: components/offline_pages/offline_page_model.h
diff --git a/components/offline_pages/offline_page_model.h b/components/offline_pages/offline_page_model.h
index 99d306cbf648f1bd121f6847da232d842efe1372..4728592dbabe767f5ee169d8851d07c5f3bdc9a4 100644
--- a/components/offline_pages/offline_page_model.h
+++ b/components/offline_pages/offline_page_model.h
@@ -40,8 +40,10 @@ static const int64_t kInvalidOfflineId = 0;
 
 struct ClientId;
 
+class ClientPolicyController;
 struct OfflinePageItem;
 class OfflinePageMetadataStore;
+class OfflinePageStorageManager;
 
 // Service for saving pages offline, storing the offline copy and metadata, and
 // retrieving them upon request.
@@ -257,9 +259,14 @@ class OfflinePageModel : public KeyedService, public base::SupportsUserData {
                                int64_t free_space_bytes,
                                bool reporting_after_delete);
 
+  // Returns the policy controller.
+  ClientPolicyController* GetPolicyController();
+
   // Methods for testing only:
   OfflinePageMetadataStore* GetStoreForTesting();
 
+  OfflinePageStorageManager* GetStorageManager();
+
   bool is_loaded() const { return is_loaded_; }
 
  private:
@@ -381,6 +388,13 @@ class OfflinePageModel : public KeyedService, public base::SupportsUserData {
   // Delayed tasks that should be invoked after the loading is done.
   std::vector<base::Closure> delayed_tasks_;
 
+  // Controller of the client policies.
+  std::unique_ptr<ClientPolicyController> policy_controller_;
+
+  // Manager for the storage consumed by archives and responsible for
+  // automatic page clearing.
+  std::unique_ptr<OfflinePageStorageManager> storage_manager_;
+
   base::WeakPtrFactory<OfflinePageModel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageModel);