Remove unsafe cast from ImageTransportSurfaceOverlayMac::ScheduleCALayer.

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 <CoreVideo/CVPixelBuffer.h>
 #include <IOSurface/IOSurface.h>
 #include <stdint.h>
@@ skipping 53 matching lines @@
   gfx::GenericSharedMemoryId io_surface_id() const { return io_surface_id_; }
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface();
   base::ScopedCFTypeRef<CVPixelBufferRef> cv_pixel_buffer();
 
   // Whether checking IOSurfaceIsInUse() will actually provide a meaningful
   // signal about whether the Window Server is still using the IOSurface.
   bool CanCheckIOSurfaceIsInUse() const;
 
   static unsigned GetInternalFormatForTesting(gfx::BufferFormat format);
 
+  // Downcasts from |image|. Returns |nullptr| on failure.
+  static GLImageIOSurface* FromGLImage(GLImage* image);
+
  protected:
   ~GLImageIOSurface() override;
 
  private:
+  Type GetType() const override;
   class RGBConverter;
 
   const gfx::Size size_;
 
   // The "internalformat" exposed to the command buffer, which may not be
   // "internalformat" requested by the client.
   const unsigned internalformat_;
 
   // The "internalformat" requested by the client.
   const unsigned client_internalformat_;
 
   gfx::BufferFormat format_;
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface_;
   base::ScopedCFTypeRef<CVPixelBufferRef> cv_pixel_buffer_;
   gfx::GenericSharedMemoryId io_surface_id_;
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(GLImageIOSurface);
 };
 
 }  // namespace gl
 
 #endif  // UI_GL_GL_IMAGE_IO_SURFACE_H_