Implementing directional selection strategy in Blink.

Source/core/editing/VisibleSelection.h

Index: Source/core/editing/VisibleSelection.h
diff --git a/Source/core/editing/VisibleSelection.h b/Source/core/editing/VisibleSelection.h
index 75856ea84e53dc33c3ed5fbc93a903cfc1826c55..22caa9c19f66104ba69abae2873a9beecb4fa817 100644
--- a/Source/core/editing/VisibleSelection.h
+++ b/Source/core/editing/VisibleSelection.h
@@ -30,6 +30,7 @@
 #include "core/editing/SelectionType.h"
 #include "core/editing/TextGranularity.h"
 #include "core/editing/VisiblePosition.h"
+#include "core/editing/VisibleUnits.h"
 
 namespace blink {
 
@@ -146,8 +147,8 @@ public:
     void showTreeForThis() const;
 #endif
 
-    void setStartRespectingGranularity(TextGranularity);
-    void setEndRespectingGranularity(TextGranularity);
+    void setStartRespectingGranularity(TextGranularity, EWordSide defaultWordSide = RightWordIfOnBoundary);
+    void setEndRespectingGranularity(TextGranularity, EWordSide defaultWordSide = RightWordIfOnBoundary);
 
 private:
     void validate(TextGranularity = CharacterGranularity);
@@ -183,7 +184,7 @@ private:
 inline bool operator==(const VisibleSelection& a, const VisibleSelection& b)
 {
     return a.start() == b.start() && a.end() == b.end() && a.affinity() == b.affinity() && a.isBaseFirst() == b.isBaseFirst()
-        && a.isDirectional() == b.isDirectional();
+        && a.isDirectional() == b.isDirectional() && a.base() == b.base() && a.extent() == b.extent();

[yosin_UTC9, 2015/04/16 04:11:26]

Note: I assume this change will be kicked out from this patch, since another
patch has this change.

[mfomitchev1, 2015/04/17 00:13:51]

Done.

 }
 
 inline bool operator!=(const VisibleSelection& a, const VisibleSelection& b)