Split Android-specific dependency from BackgroundLoaderOffliner. Create a subfolder of c/b/offline_…

components/offline_pages/core/background/load_termination_listener.h

Index: components/offline_pages/core/background/load_termination_listener.h
diff --git a/components/offline_pages/core/background/load_termination_listener.h b/components/offline_pages/core/background/load_termination_listener.h
new file mode 100644
index 0000000000000000000000000000000000000000..09b61cadc4fc31742f6ed38ed5330f0bfe9c8b32
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+++ b/components/offline_pages/core/background/load_termination_listener.h
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+// Copyright 2017 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 COMPONENTS_OFFLINE_PAGES_CORE_BACKGROUND_LOAD_TERMINATION_LISTENER_H_
+#define COMPONENTS_OFFLINE_PAGES_CORE_BACKGROUND_LOAD_TERMINATION_LISTENER_H_
+
+#include "components/offline_pages/core/background/offliner.h"
+
+namespace offline_pages {
+
+// The OS-specific instance of this class is created and passed to
+// BackgroundLoaderOffliner which takes lifetime ownership of it.
+// When listener receives signals requiring immediate termination of loading,
+// it should call Offliner::TerminateLoadIfInProgress().
+class LoadTerminationListener {
+ public:
+  LoadTerminationListener() = default;
+  virtual ~LoadTerminationListener() = default;
+
+  // Called by Offliner when it takes ownership of this listener. Used to
+  // cache pointer back to offliner to terminate the load.
+  void set_offliner(Offliner* offliner) { offliner_ = offliner; }
+
+ protected:
+  // Raw pointer because this class is owned by Offliner.
+  Offliner* offliner_ = nullptr;
+  DISALLOW_COPY_AND_ASSIGN(LoadTerminationListener);
+};
+
+}  // namespace offline_pages
+
+#endif  // COMPONENTS_OFFLINE_PAGES_CORE_BACKGROUND_LOAD_TERMINATION_LISTENER_H_