scheduler: Move the Blink scheduler into Blink

components/scheduler/renderer/render_widget_signals.h

-// Copyright 2015 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_SCHEDULER_RENDERER_RENDER_WIDGET_SIGNALS_H_
-#define COMPONENTS_SCHEDULER_RENDERER_RENDER_WIDGET_SIGNALS_H_
-
-#include <memory>
-
-#include "base/trace_event/trace_event.h"
-#include "base/trace_event/trace_event_argument.h"
-#include "components/scheduler/scheduler_export.h"
-
-namespace scheduler {
-
-class RenderWidgetSchedulingState;
-
-class SCHEDULER_EXPORT RenderWidgetSignals {
- public:
-  class SCHEDULER_EXPORT Observer {
-   public:
-    virtual ~Observer() {}
-
-    // If |hidden| is true then all render widgets managed by this renderer
-    // process have been hidden.
-    // If |hidden| is false at least one render widget managed by this renderer
-    // process has become visible and the renderer is no longer hidden.
-    // Will be called on the main thread.
-    virtual void SetAllRenderWidgetsHidden(bool hidden) = 0;
-
-    // Tells the observer whether or not we have at least one touch handler on
-    // a visible render widget. Will be called on the main thread.
-    virtual void SetHasVisibleRenderWidgetWithTouchHandler(
-        bool has_visible_render_widget_with_touch_handler) = 0;
-  };
-
-  explicit RenderWidgetSignals(Observer* observer);
-
-  std::unique_ptr<RenderWidgetSchedulingState> NewRenderWidgetSchedulingState();
-
-  void AsValueInto(base::trace_event::TracedValue* state) const;
-
- private:
-  friend class RenderWidgetSchedulingState;
-
-  void IncNumVisibleRenderWidgets();
-  void DecNumVisibleRenderWidgets();
-  void IncNumVisibleRenderWidgetsWithTouchHandlers();
-  void DecNumVisibleRenderWidgetsWithTouchHandlers();
-
-  Observer* observer_;  // NOT OWNED
-  int num_visible_render_widgets_;
-  int num_visible_render_widgets_with_touch_handlers_;
-};
-
-}  // namespace scheduler
-
-#endif  // COMPONENTS_SCHEDULER_RENDERER_RENDER_WIDGET_SIGNALS_H_