Introduce BackwardGraphemeBoundaryStateMachine

third_party/WebKit/Source/core/editing/state_machines/StateMachineTestUtil.h

Index: third_party/WebKit/Source/core/editing/state_machines/StateMachineTestUtil.h
diff --git a/third_party/WebKit/Source/core/editing/state_machines/StateMachineTestUtil.h b/third_party/WebKit/Source/core/editing/state_machines/StateMachineTestUtil.h
new file mode 100644
index 0000000000000000000000000000000000000000..f3f20604d7e13282a71d81223c2aaf58f86d7fde
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+++ b/third_party/WebKit/Source/core/editing/state_machines/StateMachineTestUtil.h
@@ -0,0 +1,29 @@
+// 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.
+
+#include "wtf/text/Unicode.h"
+
+#include <string>
+#include <vector>
+
+namespace blink {
+
+class BackwardGraphemeBoundaryStateMachine;
+
+// Processes the |machine| with preceding/following code points.
+// The result string represents the output sequence of the state machine.
+// Each character represents returned state of each action.
+// I : Invalid
+// R : NeedMoreCodeUnit (Repeat)
+// S : NeedFollowingCodeUnit (Switch)
+// F : Finished
+//
+// For example, if a state machine returns following sequence:
+//   NeedMoreCodeUnit, NeedFollowingCodeUnit, Finished
+// the returned string will be "RSF".
+std::string processSequenceBackward(
+    BackwardGraphemeBoundaryStateMachine*,
+    const std::vector<UChar32>& preceding);
+
+} // namespace blink