Add PERSISTENT_MAP usage for GpuMemoryBuffers.

ui/ozone/gpu/gpu_memory_buffer_factory_ozone_native_buffer.cc

Index: ui/ozone/gpu/gpu_memory_buffer_factory_ozone_native_buffer.cc
diff --git a/ui/ozone/gpu/gpu_memory_buffer_factory_ozone_native_buffer.cc b/ui/ozone/gpu/gpu_memory_buffer_factory_ozone_native_buffer.cc
index 51ff149976c75b71dda485ed30d42ae6305df825..146573a264e325453c1921ad3a68ca730c421497 100644
--- a/ui/ozone/gpu/gpu_memory_buffer_factory_ozone_native_buffer.cc
+++ b/ui/ozone/gpu/gpu_memory_buffer_factory_ozone_native_buffer.cc
@@ -113,6 +113,10 @@ SurfaceFactoryOzone::BufferUsage GetOzoneUsageFor(
       return SurfaceFactoryOzone::MAP;
     case gfx::GpuMemoryBuffer::SCANOUT:
       return SurfaceFactoryOzone::SCANOUT;
+    case gfx::GpuMemoryBuffer::PERSISTENT_MAP:
+      // TODO(alexst): This is not supported by ozone (yet?).

[reveman, 2015/05/20 14:26:08]

I think you should add the SurfaceFactoryOzone::PERSISTENT_MAP enum value as 
part of this patch. We have SurfaceFactoryOzone::MAP already and that's not
supported yet.

[danakj, 2015/05/20 17:51:14]

Done.

+      NOTREACHED();
+      return SurfaceFactoryOzone::MAP;

[alexst (slow to review), 2015/05/20 12:43:37]

Add a new enum type to SurfaceFactoryOzone, please. We have a way to query
support from the platform via CanCreateNativePixmap(BufferUsage usage). It is
valid to return SurfaceFactoryOzone::PERSISTENT_MAP here.

[danakj, 2015/05/20 17:51:14]

Done.

   }
 
   NOTREACHED();