Mac Overlays: Wire up overlays on Mac

ui/gl/gl_image_io_surface.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 UI_GL_GL_IMAGE_IO_SURFACE_H_
 #define UI_GL_GL_IMAGE_IO_SURFACE_H_
 
 #include <IOSurface/IOSurface.h>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/threading/thread_checker.h"
 #include "ui/gfx/gpu_memory_buffer.h"
 #include "ui/gl/gl_image.h"
 
+#if defined(__OBJC__)
+@class CALayer;
+#else
+typedef void* CALayer;
+#endif
+
 namespace gfx {
 
 class GL_EXPORT GLImageIOSurface : public GLImage {
  public:
   GLImageIOSurface(const gfx::Size& size, unsigned internalformat);
 
   bool Initialize(IOSurfaceRef io_surface, GpuMemoryBuffer::Format format);
 
   // Overridden from GLImage:
   void Destroy(bool have_context) override;
   gfx::Size GetSize() override;
   unsigned GetInternalFormat() override;
   bool BindTexImage(unsigned target) override;
   void ReleaseTexImage(unsigned target) override {}
   bool CopyTexSubImage(unsigned target,
                        const Point& offset,
                        const Rect& rect) override;
   void WillUseTexImage() override {}
   void DidUseTexImage() override {}
   void WillModifyTexImage() override {}
   void DidModifyTexImage() override {}
   bool ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                             int z_order,
                             OverlayTransform transform,
                             const Rect& bounds_rect,
                             const RectF& crop_rect) override;
 
+  static void SetLayerForWidget(gfx::AcceleratedWidget widget,
+                                CALayer* layer);
+
  protected:
   ~GLImageIOSurface() override;
 
  private:
   const gfx::Size size_;
   const unsigned internalformat_;
   GpuMemoryBuffer::Format format_;
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface_;
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(GLImageIOSurface);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_IMAGE_IO_SURFACE_H_