Propagate drag-and-drop key modifiers to WebView's guest renderer.

third_party/WebKit/public/platform/WebDragData.h

Index: third_party/WebKit/public/platform/WebDragData.h
diff --git a/third_party/WebKit/public/platform/WebDragData.h b/third_party/WebKit/public/platform/WebDragData.h
index dd3254a75d873cd50c3bd189765f15cabd23f638..3e5fc11ec1b0f913f42a45e52abfb7a83db4ba63 100644
--- a/third_party/WebKit/public/platform/WebDragData.h
+++ b/third_party/WebKit/public/platform/WebDragData.h
@@ -137,6 +137,16 @@ public:
         m_filesystemId = filesystemId;
     }
 
+    int modifierKeyState() const
+    {
+        return m_modifierKeyState;
+    }
+
+    void setModifierKeyState(int state)
+    {
+        m_modifierKeyState = state;
+    }
+
 private:
     bool m_valid;
     WebVector<Item> m_itemList;