Add gpu::BufferBacking::shared_memory_handle()

gpu/BUILD.gn

 # 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.
 
 import("//testing/libfuzzer/fuzzer_test.gni")
 import("//testing/test.gni")
 import("//build/config/ui.gni")
 
 config("gpu_implementation") {
   defines = [ "GPU_IMPLEMENTATION" ]
@@ skipping 213 matching lines @@
     "command_buffer/client/fenced_allocator_test.cc",
     "command_buffer/client/gles2_implementation_unittest.cc",
     "command_buffer/client/mapped_memory_unittest.cc",
     "command_buffer/client/program_info_manager_unittest.cc",
     "command_buffer/client/query_tracker_unittest.cc",
     "command_buffer/client/ring_buffer_test.cc",
     "command_buffer/client/transfer_buffer_unittest.cc",
     "command_buffer/client/vertex_array_object_manager_unittest.cc",
     "command_buffer/common/activity_flags_unittest.cc",
     "command_buffer/common/bitfield_helpers_test.cc",
+    "command_buffer/common/buffer_unittest.cc",
     "command_buffer/common/command_buffer_shared_test.cc",
     "command_buffer/common/debug_marker_manager_unittest.cc",
     "command_buffer/common/discardable_handle_unittest.cc",
     "command_buffer/common/gles2_cmd_format_test.cc",
     "command_buffer/common/gles2_cmd_format_test_autogen.h",
     "command_buffer/common/gles2_cmd_utils_unittest.cc",
     "command_buffer/common/id_allocator_test.cc",
     "command_buffer/common/id_type_unittest.cc",
     "command_buffer/common/unittest_main.cc",
     "command_buffer/service/buffer_manager_unittest.cc",
@@ skipping 218 matching lines @@
       "//base/third_party/dynamic_annotations",
       "//gpu/command_buffer/common:gles2_utils",
       "//ui/gfx/geometry",
       "//ui/gl",
       "//ui/gl:test_support",
     ]
 
     libfuzzer_options = [ "max_len=16384" ]
   }
 }