ozone: drm: Fix graphics buffer handle leak in DrmConsoleBuffer

ui/ozone/platform/drm/test/mock_drm_device.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/test/mock_drm_device.h"
 
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 
 #include "base/logging.h"
@@ skipping 201 matching lines @@
   return true;
 }
 
 void MockDrmDevice::DestroyDumbBuffer(const SkImageInfo& info,
                                       uint32_t handle,
                                       uint32_t stride,
                                       void* pixels) {
   delete[] static_cast<char*>(pixels);
 }
 
+bool MockDrmDevice::CloseBufferHandle(uint32_t handle) {
+  return true;
+}
+
 bool MockDrmDevice::CommitProperties(drmModePropertySet* properties,
                                      uint32_t flags,
                                      const PageFlipCallback& callback) {
   return false;
 }
 
 void MockDrmDevice::RunCallbacks() {
   while (!callbacks_.empty()) {
     PageFlipCallback callback = callbacks_.front();
     callbacks_.pop();
     callback.Run(0, 0, 0);
   }
 }
 
 }  // namespace ui