HTMLTextAreaElement.setSelectionRange should not change focus.

Source/core/html/HTMLTextAreaElement.h

Index: Source/core/html/HTMLTextAreaElement.h
diff --git a/Source/core/html/HTMLTextAreaElement.h b/Source/core/html/HTMLTextAreaElement.h
index d0e86887aeddd82ede8bd53014ee0ee8c6c950ce..ed8efd1d5b58ece25f8dfe5b955c88136d1250c0 100644
--- a/Source/core/html/HTMLTextAreaElement.h
+++ b/Source/core/html/HTMLTextAreaElement.h
@@ -76,7 +76,8 @@ private:
     void updateValue() const;
     virtual void setInnerEditorValue(const String&) OVERRIDE;
     void setNonDirtyValue(const String&);
-    void setValueCommon(const String&, TextFieldEventBehavior);
+    // Returns true if |m_value| is updated.
+    bool setValueCommon(const String&, TextFieldEventBehavior);
 
     virtual bool supportsPlaceholder() const OVERRIDE { return true; }
     virtual void updatePlaceholderText() OVERRIDE;