Separate SwipeRefreshHandler and ContentViewCore

ui/android/overscroll_refresh_handler.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 UI_ANDROID_OVERSCROLL_REFRESH_HANDLER_H
+#define UI_ANDROID_OVERSCROLL_REFRESH_HANDLER_H
+
+#include "base/android/scoped_java_ref.h"
+#include "ui/android/ui_android_export.h"
+
+namespace ui {
+
+class UI_ANDROID_EXPORT OverscrollRefreshHandler {
+ public:
+  explicit OverscrollRefreshHandler(
+      const base::android::JavaRef<jobject>& j_overscroll_refresh_handler);
+  ~OverscrollRefreshHandler();
+  // Signals the start of an overscrolling pull. Returns whether the handler
+  // will consume the overscroll gesture, in which case it will receive the
+  // remaining pull updates.
+  bool PullStart();
+
+  // Signals a pull update, where |delta| is in device pixels.
+  void PullUpdate(float delta);
+
+  // Signals the release of the pull, and whether the release is allowed to
+  // trigger the refresh action.
+  void PullRelease(bool allow_refresh);
+
+  // Reset the active pull state.
+  void PullReset();
+
+ private:
+  base::android::ScopedJavaGlobalRef<jobject> j_overscroll_refresh_handler_;
+};
+}
+
+#endif  // UI_ANDROID_OVERSCROLL_REFRESH_HANDLER_H