refactor: rename the atom directory to shell

shell/common/heap_snapshot.h

@@ -0,0 +1,17 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_COMMON_HEAP_SNAPSHOT_H_
+#define ATOM_COMMON_HEAP_SNAPSHOT_H_
+
+#include "base/files/file.h"
+#include "v8/include/v8.h"
+
+namespace atom {
+
+bool TakeHeapSnapshot(v8::Isolate* isolate, base::File* file);
+
+}  // namespace atom
+
+#endif  // ATOM_COMMON_HEAP_SNAPSHOT_H_