ozone: Implement zero/one-copy texture for Ozone GBM.

ui/ozone/platform/drm/gpu/gbm_buffer.cc

 // Copyright 2014 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.
 
 #include "ui/ozone/platform/drm/gpu/gbm_buffer.h"
 
 #include <drm.h>
 #include <fcntl.h>
 #include <gbm.h>
 #include <xf86drm.h>
@@ skipping 35 matching lines @@
 
 // static
 scoped_refptr<GbmBuffer> GbmBuffer::CreateBuffer(
     const scoped_refptr<GbmDevice>& gbm,
     SurfaceFactoryOzone::BufferFormat format,
     const gfx::Size& size,
     bool scanout) {
   TRACE_EVENT2("drm", "GbmBuffer::CreateBuffer", "device",
                gbm->device_path().value(), "size", size.ToString());
   unsigned flags = GBM_BO_USE_RENDERING;
+  // GBM_BO_USE_SCANOUT is the hint of x-tiling.
   if (scanout)
     flags |= GBM_BO_USE_SCANOUT;
   gbm_bo* bo = gbm_bo_create(gbm->device(), size.width(), size.height(),
                              GetGbmFormatFromBufferFormat(format), flags);
   if (!bo)
     return NULL;
 
   scoped_refptr<GbmBuffer> buffer(new GbmBuffer(gbm, bo, scanout));
   if (scanout && !buffer->GetFramebufferId())
     return NULL;
@@ skipping 74 matching lines @@
   }
 
   gfx::Size pixmap_size = buffer_->GetSize();
   // If the required size is not integer-sized, round it to the next integer.
   *required_size = gfx::ToCeiledSize(
       gfx::SizeF(display_bounds.width() / crop_rect.width(),
                  display_bounds.height() / crop_rect.height()));
   return pixmap_size != *required_size;
 }
 
+NativePixmap::BufferUsage GbmPixmap::GetBufferUsage() const {
+  return buffer_->GetFramebufferId() ? SCANOUT : MAP;
+}
+
+void* GbmPixmap::Map() {
+  NOTREACHED();
+  return nullptr;
+}
+
+void GbmPixmap::Unmap() {
+  NOTREACHED();
+}
+
 }  // namespace ui