[exo] Clean up BeginFrame distribution & add acks in Surface.

components/exo/surface.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_EXO_SURFACE_H_
 #define COMPONENTS_EXO_SURFACE_H_
 
 #include <list>
 #include <memory>
 #include <set>
 #include <utility>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/resources/transferable_resource.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/local_surface_id_allocator.h"
 #include "components/exo/compositor_frame_sink.h"
 #include "components/exo/compositor_frame_sink_holder.h"
 #include "third_party/skia/include/core/SkBlendMode.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_observer.h"
 #include "ui/compositor/compositor_vsync_manager.h"
@@ skipping 27 matching lines @@
 
 // The pointer class is currently the only cursor provider class but this can
 // change in the future when better hardware cursor support is added.
 using CursorProvider = Pointer;
 
 // This class represents a rectangular area that is displayed on the screen.
 // It has a location, size and pixel contents.
 class Surface : public ui::ContextFactoryObserver,
                 public aura::WindowObserver,
                 public ui::PropertyHandler,
-                public ui::CompositorVSyncManager::Observer {
+                public ui::CompositorVSyncManager::Observer,
+                public cc::BeginFrameObserverBase {
  public:
   using PropertyDeallocator = void (*)(int64_t value);
 
   Surface();
   ~Surface() override;
 
   // Type-checking downcast routine.
   static Surface* AsSurface(const aura::Window* window);
 
   aura::Window* window() { return window_.get(); }
@@ skipping 109 matching lines @@
   void AddSurfaceObserver(SurfaceObserver* observer);
   void RemoveSurfaceObserver(SurfaceObserver* observer);
   bool HasSurfaceObserver(const SurfaceObserver* observer) const;
 
   // Returns a trace value representing the state of the surface.
   std::unique_ptr<base::trace_event::TracedValue> AsTracedValue() const;
 
   // Call this to indicate that surface is being scheduled for a draw.
   void WillDraw();
 
-  // Returns true when there's an active frame callback that requires a
-  // BeginFrame() call.
-  bool NeedsBeginFrame() const;
-
-  // Call this to indicate that it's a good time to start producing a new frame.
-  void BeginFrame(base::TimeTicks frame_time);
+  // Called when the begin frame source has changed.
+  void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source);
 
   // Check whether this Surface and its children need to create new cc::Surface
   // IDs for their contents next time they get new buffer contents.
   void CheckIfSurfaceHierarchyNeedsCommitToNewSurfaces();
 
   // Returns the active contents size.
   gfx::Size content_size() const { return content_size_; }
 
   // Overridden from ui::ContextFactoryObserver:
   void OnLostResources() override;
 
   // Overridden from aura::WindowObserver:
   void OnWindowAddedToRootWindow(aura::Window* window) override;
   void OnWindowRemovingFromRootWindow(aura::Window* window,
                                       aura::Window* new_root) override;
 
   // Overridden from ui::CompositorVSyncManager::Observer:
   void OnUpdateVSyncParameters(base::TimeTicks timebase,
                                base::TimeDelta interval) override;
 
   bool HasPendingDamageForTesting(const gfx::Rect& damage) const {
     return pending_damage_.contains(gfx::RectToSkIRect(damage));
   }
 
+  // Overridden from cc::BeginFrameObserverBase:
+  bool OnBeginFrameDerivedImpl(const cc::BeginFrameArgs& args) override;
+  void OnBeginFrameSourcePausedChanged(bool paused) override {}
+
  private:
   struct State {
     State();
     ~State();
 
     bool operator==(const State& other);
     bool operator!=(const State& other) { return !(*this == other); }
 
     SkRegion opaque_region;
     SkRegion input_region;
@@ skipping 40 matching lines @@
   // Updates current_resource_ with a new resource id corresponding to the
   // contents of the attached buffer (or id 0, if no buffer is attached).
   // UpdateSurface must be called afterwards to ensure the release callback
   // will be called.
   void UpdateResource(bool client_usage);
 
   // Updates the current Surface with a new frame referring to the resource in
   // current_resource_.
   void UpdateSurface(bool full_damage);
 
+  // Adds/Removes begin frame observer based on state.
+  void UpdateNeedsBeginFrame();
+
   // This returns true when the surface has some contents assigned to it.
   bool has_contents() const { return !!current_buffer_.buffer(); }
 
   // This window has the layer which contains the Surface contents.
   std::unique_ptr<aura::Window> window_;
 
   // This is true if it's possible that the layer properties (size, opacity,
   // etc.) may have been modified since the last commit. Attaching a new
   // buffer with the same size as the old shouldn't set this to true.
   bool has_pending_layer_changes_ = true;
@@ skipping 87 matching lines @@
 
   // Surface observer list. Surface does not own the observers.
   base::ObserverList<SurfaceObserver, true> observers_;
 
   // A reference factory that uses the compositor frame sink holder provided
   // to this class to construct surface references. This object is passed to
   // ui::Layer::SetShowSurface because the layer needs to know how to add
   // references to surfaces.
   scoped_refptr<cc::SurfaceReferenceFactory> surface_reference_factory_;
 
+  // The begin frame source being observed.
+  cc::BeginFrameSource* begin_frame_source_ = nullptr;
+  bool begin_frame_observer_added_ = false;

[reveman, 2017/03/13 12:13:35]

nit: s/begin_frame_observer_added_/needs_begin_frame_| as adding the observer is
no longer something we do once

[Eric Seckler, 2017/03/14 09:27:14]

Done.

+  cc::BeginFrameAck current_begin_frame_ack_;
+
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_SURFACE_H_