Add ChildMemoryCoordinator::PurgeMemory()

content/child/memory/child_memory_coordinator_impl.h

 // Copyright 2016 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_CHILD_MEMORY_CHILD_MEMORY_COORDINATOR_IMPL_H_
 #define CONTENT_CHILD_MEMORY_CHILD_MEMORY_COORDINATOR_IMPL_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/memory_coordinator_client.h"
 #include "content/common/child_memory_coordinator.mojom.h"
@@ skipping 17 matching lines @@
 class CONTENT_EXPORT ChildMemoryCoordinatorImpl
     : NON_EXPORTED_BASE(public mojom::ChildMemoryCoordinator) {
  public:
   // Returns the instance of ChildMemoryCoordinatorImpl. Could be nullptr.
   static ChildMemoryCoordinatorImpl* GetInstance();
 
   ChildMemoryCoordinatorImpl(mojom::MemoryCoordinatorHandlePtr parent,
                              ChildMemoryCoordinatorDelegate* delegate);
   ~ChildMemoryCoordinatorImpl() override;
 
+  // Requests purging memory to clients.
+  void PurgeMemory();
+
   // mojom::ChildMemoryCoordinator implementations:
   void OnStateChange(mojom::MemoryState state) override;
 
  protected:
   ChildMemoryCoordinatorDelegate* delegate() { return delegate_; }
 
  private:
   friend class ChildMemoryCoordinatorImplTest;
 
   mojo::Binding<mojom::ChildMemoryCoordinator> binding_;
   mojom::MemoryCoordinatorHandlePtr parent_;
   ChildMemoryCoordinatorDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildMemoryCoordinatorImpl);
 };
 
 // Factory function for creating a ChildMemoryCoordinator for the current
 // platform. Doesn't take the ownership of |delegate|.
 CONTENT_EXPORT std::unique_ptr<ChildMemoryCoordinatorImpl>
 CreateChildMemoryCoordinator(mojom::MemoryCoordinatorHandlePtr parent,
                              ChildMemoryCoordinatorDelegate* delegate);
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_MEMORY_CHILD_MEMORY_COORDINATOR_IMPL_H_