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

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

Index: ui/ozone/platform/drm/gpu/gbm_buffer.cc
diff --git a/ui/ozone/platform/drm/gpu/gbm_buffer.cc b/ui/ozone/platform/drm/gpu/gbm_buffer.cc
index 362f77c8dd6566ca08c6b26fea9341c950f3e8ff..d72806469750313e09697cc5864fb9b463763361 100644
--- a/ui/ozone/platform/drm/gpu/gbm_buffer.cc
+++ b/ui/ozone/platform/drm/gpu/gbm_buffer.cc
@@ -11,6 +11,7 @@
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
+#include "ui/gfx/gpu_memory_buffer.h"

[reveman, 2015/05/14 13:22:03]

This code should not know about GpuMemoryBuffers.

 #include "ui/ozone/platform/drm/gpu/gbm_device.h"
 
 namespace ui {
@@ -51,8 +52,9 @@ scoped_refptr<GbmBuffer> GbmBuffer::CreateBuffer(
   TRACE_EVENT2("drm", "GbmBuffer::CreateBuffer", "device",
                gbm->device_path().value(), "size", size.ToString());
   unsigned flags = GBM_BO_USE_RENDERING;
-  if (scanout)
-    flags |= GBM_BO_USE_SCANOUT;
+  // SCANOUT allocates continuous memory, so better for performance even if
+  // |scanout| is false.
+  flags |= GBM_BO_USE_SCANOUT;
   gbm_bo* bo = gbm_bo_create(gbm->device(), size.width(), size.height(),
                              GetGbmFormatFromBufferFormat(format), flags);
   if (!bo)
@@ -98,4 +100,8 @@ int GbmPixmap::GetDmaBufPitch() {
   return gbm_bo_get_stride(buffer_->bo());
 }
 
+NativePixmap::BufferUsage GbmPixmap::GetBufferUsage() const {
+  return buffer_->GetFramebufferId() ? SCANOUT : MAP;
+}
+
 }  // namespace ui