Implementing directional selection strategy in Blink.

Source/core/editing/SelectionStrategy.h

+// Copyright 2015 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.
+
+#ifndef SelectionStrategy_h
+#define SelectionStrategy_h
+
+namespace blink {
+
+enum class SelectionStrategy {
+    // Always using CharacterGranularity
+    Character,
+    // Switches between WordGranularity and CharacterGranularity
+    // Depending on whether the selection or growing or shrinking
+    Direction,
+};
+
+} // namespace blink
+
+#endif // SelectionStrategy_h