Revert IOSurface CoreAnimation simplifications on ccameron@'s advice.

content/browser/compositor/io_surface_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_COMPOSITOR_IO_SURFACE_LAYER_MAC_H_
-#define CONTENT_BROWSER_COMPOSITOR_IO_SURFACE_LAYER_MAC_H_
+#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 <IOSurface/IOSurfaceAPI.h>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/ref_counted.h"
 #include "base/timer/timer.h"
 #include "ui/gfx/size.h"
-#include "ui/gl/scoped_cgl.h"
 
 @class IOSurfaceLayer;
 
 namespace content {
-class IOSurfaceLayerHelper;
+class CompositingIOSurfaceMac;
+class CompositingIOSurfaceContext;
 
 // The interface through which the IOSurfaceLayer calls back into
 // the structrue that created it (RenderWidgetHostViewMac or
 // BrowserCompositorViewMac).
 class IOSurfaceLayerClient {
  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 IOSurfaceLayerShouldAckImmediately() 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 IOSurfaceLayerDidDrawFrame() = 0;
 
   // Called when an error prevents the frame from being drawn.
   virtual void IOSurfaceLayerHitError() = 0;
 };
 
-}  // namespace content
+// IOSurfaceLayerHelper provides C++ functionality needed for the
+// IOSurfaceLayer class, and does most of the heavy lifting for the
+// class.
+// TODO(ccameron): This class should own IOSurfaceLayer, rather than
+// vice versa.
+class IOSurfaceLayerHelper {
+ public:
+  IOSurfaceLayerHelper(IOSurfaceLayerClient* client,
+                                  IOSurfaceLayer* layer);
+  ~IOSurfaceLayerHelper();
 
-// The CoreAnimation layer for drawing accelerated content.
-@interface IOSurfaceLayer : CAOpenGLLayer {
- @private
-  content::IOSurfaceLayerClient* client_;
-  scoped_ptr<content::IOSurfaceLayerHelper> helper_;
+  // Called when the IOSurfaceLayer gets a new frame.
+  void GotNewFrame();
+
+  // Called whenever -[IOSurfaceLayer setNeedsDisplay] is called.
+  void SetNeedsDisplay();
+
+  // Called whenever -[IOSurfaceLayer canDrawInCGLContext] is called,
+  // to determine if a new frame should be drawn.
+  bool CanDraw();
+
+  // Called whenever -[IOSurfaceLayer 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::IOSurfaceLayerClient* const client_;
+
+  // The layer that owns this helper.
+  IOSurfaceLayer* 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 IOSurface being drawn by this layer.
-  base::ScopedCFTypeRef<IOSurfaceRef> io_surface_;
+  // 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<IOSurfaceLayerHelper> timer_;
+};
 
-  // The size of the frame in pixels. This will be less or equal than the pixel
-  // size of |io_surface_|.
-  gfx::Size frame_pixel_size_;
+}  // namespace content
 
-  // The GL texture that was bound to |io_surface_| during the last draw call,
-  // along with the context that was done in, and the value of |io_surface_| at
-  // the time of the bind.
-  GLuint io_surface_texture_;
-  base::ScopedTypeRef<CGLContextObj> io_surface_texture_context_;
-  base::ScopedCFTypeRef<IOSurfaceRef> io_surface_texture_io_surface_;
+// The CoreAnimation layer for drawing accelerated content.
+@interface IOSurfaceLayer : CAOpenGLLayer {
+ @private
+  scoped_refptr<content::CompositingIOSurfaceMac> iosurface_;
+  scoped_refptr<content::CompositingIOSurfaceContext> context_;
 
-  // The CGL renderer ID, captured at draw time.
-  GLint cgl_renderer_id_;
+  scoped_ptr<content::IOSurfaceLayerHelper> helper_;
 }
 
 - (id)initWithClient:(content::IOSurfaceLayerClient*)client
      withScaleFactor:(float)scale_factor;
 
-// Called when a new frame is received.
-- (void)gotFrameWithIOSurface:(IOSurfaceID)io_surface_id
+- (bool)gotFrameWithIOSurface:(IOSurfaceID)io_surface_id
                 withPixelSize:(gfx::Size)pixel_size
               withScaleFactor:(float)scale_factor;
 
+// Context poison accessors.
+- (void)poisonContextAndSharegroup;
+- (bool)hasBeenPoisoned;
+
 - (float)scaleFactor;
 
 // The CGL renderer ID.
 - (int)rendererID;
 
 // 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_COMPOSITOR_IO_SURFACE_LAYER_MAC_H_
+#endif  // CONTENT_BROWSER_RENDERER_HOST_COMPOSITING_IOSURFACE_LAYER_MAC_H_