Make DOMStorageContextWrapper a client of memory coordinator

content/browser/dom_storage/dom_storage_context_wrapper.h

 // Copyright 2013 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_DOM_STORAGE_DOM_STORAGE_CONTEXT_WRAPPER_H_
 #define CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_WRAPPER_H_
 
 #include <map>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/memory_pressure_listener.h"
 #include "base/memory/ref_counted.h"
+#include "components/memory_coordinator/common/memory_coordinator_client.h"
 #include "content/common/content_export.h"
 #include "content/common/storage_partition_service.mojom.h"
 #include "content/public/browser/dom_storage_context.h"
 #include "url/origin.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace shell {
 class Connector;
 }
 
 namespace storage {
 class SpecialStoragePolicy;
 }
 
 namespace content {
 
 class DOMStorageContextImpl;
 class LevelDBWrapperImpl;
 
 // This is owned by Storage Partition and encapsulates all its dom storage
 // state.
 class CONTENT_EXPORT DOMStorageContextWrapper :
     NON_EXPORTED_BASE(public DOMStorageContext),
-    public base::RefCountedThreadSafe<DOMStorageContextWrapper> {
+    public base::RefCountedThreadSafe<DOMStorageContextWrapper>,
+    public memory_coordinator::MemoryCoordinatorClient {
  public:
   // If |data_path| is empty, nothing will be saved to disk.
   DOMStorageContextWrapper(
       shell::Connector* connector,
       const base::FilePath& data_path,
       const base::FilePath& local_partition_path,
       storage::SpecialStoragePolicy* special_storage_policy);
 
   // DOMStorageContext implementation.
   void GetLocalStorageUsage(
@@ skipping 16 matching lines @@
   // Called when the BrowserContext/Profile is going away.
   void Shutdown();
 
   void Flush();
 
   // See mojom::StoragePartitionService interface.
   void OpenLocalStorage(const url::Origin& origin,
                         mojom::LevelDBObserverPtr observer,
                         mojom::LevelDBWrapperRequest request);
 
+ private:
   // Called on UI thread when the system is under memory pressure.
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
 
- private:
+  // memory_coordinator::MemoryCoordinatorClient implementation:
+  void OnMemoryStateChange(memory_coordinator::MemoryState state) override;
+
   friend class DOMStorageMessageFilter;  // for access to context()

[michaeln, 2016/09/14 19:40:49]

nit: it'd be good to keep the two OnMem and PurgeMem methods together, also plz
keep the friend dcls up at the top of the private section, thnx

[hajimehoshi, 2016/09/15 09:14:46]

Done.

   friend class SessionStorageNamespaceImpl;  // ditto
   friend class base::RefCountedThreadSafe<DOMStorageContextWrapper>;
 
   ~DOMStorageContextWrapper() override;
   DOMStorageContextImpl* context() const { return context_.get(); }
 
+  void PurgeMemory(bool aggressively);
+
   // An inner class to keep all mojo-ish details together and not bleed them
   // through the public interface.
   class MojoState;
   std::unique_ptr<MojoState> mojo_state_;
 
   // To receive memory pressure signals.
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
   scoped_refptr<DOMStorageContextImpl> context_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(DOMStorageContextWrapper);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_WRAPPER_H_