Implementing directional selection strategy in Blink.

Source/core/editing/TextGranularity.h

Index: Source/core/editing/TextGranularity.h
diff --git a/Source/core/editing/TextGranularity.h b/Source/core/editing/TextGranularity.h
index cc96da70cc55e8d0e3ed44b997322a0f5704a5e4..43831a56d4df7efaa7792056c55ee474ccbfe641 100644
--- a/Source/core/editing/TextGranularity.h
+++ b/Source/core/editing/TextGranularity.h
@@ -42,6 +42,14 @@ enum TextGranularity {
     DocumentBoundary
 };
 
+enum TextGranularityStrategy {
+    // Always using CharacterGranularity
+    GranularityStrategyDefault,
+    // Switches between WordGranularity and CharacterGranularity
+    // Depending on whether the selection or growing or shrinking
+    GranularityStrategyDirection,
+};
+
 }
 
 #endif