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

content/common/gpu/client/gpu_memory_buffer_impl_ozone_native_pixmap.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 "content/common/gpu/client/gpu_memory_buffer_impl_ozone_native_pixmap.h"
 
 #include "ui/ozone/public/client_native_pixmap_factory.h"
 #include "ui/ozone/public/surface_factory_ozone.h"
 
 namespace content {
@@ skipping 11 matching lines @@
 // static
 scoped_ptr<GpuMemoryBufferImpl>
 GpuMemoryBufferImplOzoneNativePixmap::CreateFromHandle(
     const gfx::GpuMemoryBufferHandle& handle,
     const gfx::Size& size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage,
     const DestructionCallback& callback) {
   scoped_ptr<ui::ClientNativePixmap> native_pixmap =
       ui::ClientNativePixmapFactory::GetInstance()->ImportFromHandle(
-          handle.native_pixmap_handle, size, format, usage);
+          handle.native_pixmap_handle, size, usage);
   DCHECK(native_pixmap);
   return make_scoped_ptr<GpuMemoryBufferImpl>(
       new GpuMemoryBufferImplOzoneNativePixmap(handle.id, size, format,
                                                callback, native_pixmap.Pass()));
 }
 
 bool GpuMemoryBufferImplOzoneNativePixmap::Map(void** data) {
-  return pixmap_->Map(data);
+  bool result = pixmap_->Map(data);
+  DCHECK(result);

[no sievers, 2015/08/17 17:33:18]

nit: It should be either DCHECK() or supported at runtime (since you are
returning the result here), not both.
maybe just log a warning here?
Also, should it then be: mapped_ = pixmap_->Map() and only call Unmap() below if
|mapped_|?

[dshwang, 2015/08/18 06:36:43]

Currently this code in the transition from runtime to DCHECK().
This interface is shared with MacOS and Android, so it'll not return bool after
MacOS and Android do DCHECK later.

The dcheck was introduced as reveman requested in
https://codereview.chromium.org/1134993003/#msg55
Yes, mapped_ = pixmap_->Map() is better. I removed redundant |result| local
variable

+  mapped_ = true;
+  return result;
 }
 
 void GpuMemoryBufferImplOzoneNativePixmap::Unmap() {
   pixmap_->Unmap();
+  mapped_ = false;
 }
 
 void GpuMemoryBufferImplOzoneNativePixmap::GetStride(int* stride) const {
   pixmap_->GetStride(stride);
 }
 
 gfx::GpuMemoryBufferHandle GpuMemoryBufferImplOzoneNativePixmap::GetHandle()
     const {
   gfx::GpuMemoryBufferHandle handle;
   handle.type = gfx::OZONE_NATIVE_PIXMAP;
   handle.id = id_;
   return handle;
 }
 
 }  // namespace content