[InputEvent] Support |deleteByDrag|, |insertFromDrop| and fire in sequential order

third_party/WebKit/Source/core/editing/commands/DragAndDropCommand.h

Index: third_party/WebKit/Source/core/editing/commands/DragAndDropCommand.h
diff --git a/third_party/WebKit/Source/core/editing/commands/DragAndDropCommand.h b/third_party/WebKit/Source/core/editing/commands/DragAndDropCommand.h
new file mode 100644
index 0000000000000000000000000000000000000000..180e357095173759b3b95c558f2b88a2c0acd66f
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+++ b/third_party/WebKit/Source/core/editing/commands/DragAndDropCommand.h
@@ -0,0 +1,35 @@
+// Copyright 2016 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 DragAndDropCommand_h
+#define DragAndDropCommand_h
+
+#include "core/editing/commands/CompositeEditCommand.h"
+
+namespace blink {
+
+// |DragAndDropCommand| is a dummy command. It doesn't do anything by itself,
+// but will act as a catcher for the following |DeleteByDrag| and
+// |InsertFromDrop| commands, and combine them into a single undo entry.
+// In the future when necessary, this mechanism can be generalized into a common
+// command wrapper to achieve undo group.
+class DragAndDropCommand final : public CompositeEditCommand {
+ public:
+  static DragAndDropCommand* create(Document& document) {
+    return new DragAndDropCommand(document);
+  }
+
+  bool isCommandGroupWrapper() const override;
+  bool isDragAndDropCommand() const override;
+
+ private:
+  explicit DragAndDropCommand(Document&);
+
+  void doApply(EditingState*) override;
+  InputEvent::InputType inputType() const override;
+};
+
+}  // namespace blink
+
+#endif  // DragAndDropCommand_h