Simplify IOSurface CoreAnimation code: Part 2

content/browser/renderer_host/compositing_iosurface_layer_mac.h

-// Copyright 2013 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_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_LAYER_MAC_H_
-#define CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_LAYER_MAC_H_
-
-#import <Cocoa/Cocoa.h>
-
-#include "base/mac/scoped_cftyperef.h"
-#include "base/memory/ref_counted.h"
-#include "base/timer/timer.h"
-
-@class CompositingIOSurfaceLayer;
-
-namespace content {
-class CompositingIOSurfaceMac;
-class CompositingIOSurfaceContext;
-
-// The interface through which the CompositingIOSurfaceLayer calls back into
-// the structrue that created it (RenderWidgetHostViewMac or
-// BrowserCompositorViewMac).
-class CompositingIOSurfaceLayerClient {
- public:
-  // Used to indicate that the layer should attempt to draw immediately and
-  // should (even if the draw is elided by the system), ack the frame
-  // immediately.
-  virtual bool AcceleratedLayerShouldAckImmediately() const = 0;
-
-  // Called when a frame is drawn or when, because the layer is not visible, it
-  // is known that the frame will never drawn.
-  virtual void AcceleratedLayerDidDrawFrame() = 0;
-
-  // Called when an error prevents the frame from being drawn.
-  virtual void AcceleratedLayerHitError() = 0;
-};
-
-// CompositingIOSurfaceLayerHelper provides C++ functionality needed for the
-// CompositingIOSurfaceLayer class, and does most of the heavy lifting for the
-// class.
-// TODO(ccameron): This class should own CompositingIOSurfaceLayer, rather than
-// vice versa.
-class CompositingIOSurfaceLayerHelper {
- public:
-  CompositingIOSurfaceLayerHelper(CompositingIOSurfaceLayerClient* client,
-                                  CompositingIOSurfaceLayer* layer);
-  ~CompositingIOSurfaceLayerHelper();
-
-  // Called when the CompositingIOSurfaceLayer gets a new frame.
-  void GotNewFrame();
-
-  // Called whenever -[CompositingIOSurfaceLayer setNeedsDisplay] is called.
-  void SetNeedsDisplay();
-
-  // Called whenever -[CompositingIOSurfaceLayer canDrawInCGLContext] is called,
-  // to determine if a new frame should be drawn.
-  bool CanDraw();
-
-  // Called whenever -[CompositingIOSurfaceLayer drawInCGLContext] draws a
-  // frame.
-  void DidDraw(bool success);
-
-  // Immediately re-draw the layer, even if the content has not changed, and
-  // ensure that the frame be acked.
-  void SetNeedsDisplayAndDisplayAndAck();
-
-  // Immediately draw the layer, only if one is pending, and ensure that the
-  // frame be acked.
-  void DisplayIfNeededAndAck();
-
-  // Mark a bracket in which new frames are being pumped in a restricted nested
-  // run loop. During this time frames are acked immediately and draws are
-  // deferred until the bracket ends.
-  void BeginPumpingFrames();
-  void EndPumpingFrames();
-
- private:
-  // Called whenever the frame provided in GotNewFrame should be acknowledged
-  // (this may be because it was drawn, or it may be to unblock the
-  // compositor).
-  void AckPendingFrame(bool success);
-
-  void TimerFired();
-
-  // The client that the owning layer was created with.
-  content::CompositingIOSurfaceLayerClient* const client_;
-
-  // The layer that owns this helper.
-  CompositingIOSurfaceLayer* const layer_;
-
-  // Used to track when canDrawInCGLContext should return YES. This can be
-  // in response to receiving a new compositor frame, or from any of the events
-  // that cause setNeedsDisplay to be called on the layer.
-  bool needs_display_;
-
-  // This is set when a frame is received, and un-set when the frame is drawn.
-  bool has_pending_frame_;
-
-  // Incremented every time that this layer is asked to draw but does not have
-  // new content to draw.
-  uint64 did_not_draw_counter_;
-
-  // Set when inside a BeginPumpingFrames/EndPumpingFrames block.
-  bool is_pumping_frames_;
-
-  // The browser places back-pressure on the GPU by not acknowledging swap
-  // calls until they appear on the screen. This can lead to hangs if the
-  // view is moved offscreen (among other things). Prevent hangs by always
-  // acknowledging the frame after timeout of 1/6th of a second  has passed.
-  base::DelayTimer<CompositingIOSurfaceLayerHelper> timer_;
-};
-
-}  // namespace content
-
-// The CoreAnimation layer for drawing accelerated content.
-@interface CompositingIOSurfaceLayer : CAOpenGLLayer {
- @private
-  scoped_refptr<content::CompositingIOSurfaceMac> iosurface_;
-  scoped_refptr<content::CompositingIOSurfaceContext> context_;
-
-  scoped_ptr<content::CompositingIOSurfaceLayerHelper> helper_;
-}
-
-- (content::CompositingIOSurfaceMac*)iosurface;
-- (content::CompositingIOSurfaceContext*)context;
-
-- (id)initWithIOSurface:(scoped_refptr<content::CompositingIOSurfaceMac>)
-                            iosurface
-        withScaleFactor:(float)scale_factor
-             withClient:(content::CompositingIOSurfaceLayerClient*)client;
-
-// Mark that the client is no longer valid and cannot be called back into. This
-// must be called before the layer is destroyed.
-- (void)resetClient;
-
-// Called when a new frame is received.
-- (void)gotNewFrame;
-
-// Force a draw immediately (even if this means re-displaying a previously
-// displayed frame).
-- (void)setNeedsDisplayAndDisplayAndAck;
-
-// Force a draw immediately, but only if one was requested.
-- (void)displayIfNeededAndAck;
-
-// Mark a bracket in which new frames are being pumped in a restricted nested
-// run loop.
-- (void)beginPumpingFrames;
-- (void)endPumpingFrames;
-@end
-
-#endif  // CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_LAYER_MAC_H_