Use OS_LINUX instead of USE_OZONE in ui/gfx/ when possible

ui/gfx/gpu_memory_buffer.cc

 // 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.
 
 #include "ui/gfx/gpu_memory_buffer.h"
 
 namespace gfx {
 
 GpuMemoryBufferHandle::GpuMemoryBufferHandle()
     : type(EMPTY_BUFFER), id(0), handle(base::SharedMemory::NULLHandle()) {
@@ skipping 18 matching lines @@
       handle.type = gfx::SHARED_MEMORY_BUFFER;
       handle.handle = base::SharedMemory::DuplicateHandle(source_handle.handle);
       handle.offset = source_handle.offset;
       handle.stride = source_handle.stride;
       return handle;
     }
     case gfx::OZONE_NATIVE_PIXMAP: {
       gfx::GpuMemoryBufferHandle handle;
       handle.type = gfx::OZONE_NATIVE_PIXMAP;
       handle.id = source_handle.id;
-#if defined(USE_OZONE)
+#if defined(OS_LINUX)
       handle.native_pixmap_handle =
           gfx::CloneHandleForIPC(source_handle.native_pixmap_handle);
 #endif
       return handle;
     }
     case gfx::IO_SURFACE_BUFFER:
       return source_handle;
   }
   return gfx::GpuMemoryBufferHandle();
 }
 
 }  // namespace gfx