Struct traits for gfx::Range and gfx::RangeF.

ui/gfx/range/mojo/range.mojom

Index: ui/gfx/range/mojo/range.mojom
diff --git a/ui/gfx/range/mojo/range.mojom b/ui/gfx/range/mojo/range.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..079c14611e0ec85d09de11fb10a58238ab707667
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+++ b/ui/gfx/range/mojo/range.mojom
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+// Copyright 2016 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.
+
+module gfx.mojom;
+
+struct Range {
+  uint32 start;
+  uint32 end;
+};
+
+struct RangeF {
+  float start;
+  float end;
+};