diff --git a/src/transform/localize_struct_array_assignment.h b/src/transform/localize_struct_array_assignment.h
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+++ b/src/transform/localize_struct_array_assignment.h
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+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_TRANSFORM_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_
+#define SRC_TRANSFORM_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_
+
+#include "src/transform/transform.h"
+
+namespace tint {
+namespace transform {
+
+/// This transforms replaces assignment to dynamically-indexed fixed-size arrays
+/// in structs on shader-local variables with code that copies the arrays to a
+/// temporary local variable, assigns to the local variable, and copies the
+/// array back. This is to work around FXC's compilation failure for these cases
+/// (see crbug.com/tint/1206).
+class LocalizeStructArrayAssignment
+    : public Castable<LocalizeStructArrayAssignment, Transform> {
+ public:
+  /// Constructor
+  LocalizeStructArrayAssignment();
+
+  /// Destructor
+  ~LocalizeStructArrayAssignment() override;
+
+ protected:
+  /// Runs the transform using the CloneContext built for transforming a
+  /// program. Run() is responsible for calling Clone() on the CloneContext.
+  /// @param ctx the CloneContext primed with the input program and
+  /// ProgramBuilder
+  /// @param inputs optional extra transform-specific input data
+  /// @param outputs optional extra transform-specific output data
+  void Run(CloneContext& ctx, const DataMap& inputs, DataMap& outputs) override;
+
+ private:
+  class State;
+};
+
+}  // namespace transform
+}  // namespace tint
+
+#endif  // SRC_TRANSFORM_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_