Add InputEvent and EventPacket types for batched input delivery

content/common/input/input_event.h

+// Copyright (c) 2013 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 CONTENT_COMMON_INPUT_INPUT_EVENT_H_
+#define CONTENT_COMMON_INPUT_INPUT_EVENT_H_
+
+#include "base/basictypes.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+// Base class for input types delivered to the renderer.
+class CONTENT_EXPORT InputEvent {
+ public:
+  // Used for serialization.
+  enum Type {
+    GENERIC,

[nduca, 2013/08/27 18:45:36]

In your explanation to me of this, you described it as a "non-web" input event
type. I think thats a promising approach. NonWebInput, WebInput perhaps

+    WEB_PLATFORM,
+  };
+
+  // Informs event response.
+  enum AckType {

[nduca, 2013/08/27 22:16:07]

DispositionRequirement

+    ACK_NOT_REQUIRED,
+    ACK_REQUIRED,
+    ACK_CAN_CREATE_FOLLOWUP_EVENTS

[nduca, 2013/08/27 22:16:07]

ACK_REQUIRED_AND_CAN_CREATE_FOLLOWUP

+  };
+
+  virtual ~InputEvent();
+
+  Type type;

[nduca, 2013/08/27 18:45:36]

This class still feels very structy/tightly-coupled-to-transport to me, but
strangely so.

It seems in the end state, we're going to want to have:
- a place to put fields on input events that is only relevant to the host side
of the input system
- a place to put fields on input events that is only relevant to the renderer
side of the input system
- a place to put stuff common to both
- a way to take a host input event and send its renderer-specific parts over to
the other side of the world

How does that map in this world?

+  AckType ack_type;

[nduca, 2013/08/27 22:16:07]

AckType GetDispoitionRequirements() const = 0;

+  int64 id;
+
+ protected:
+  InputEvent(Type type, AckType ack_type, int64 id);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(InputEvent);
+};
+
+}  // namespace content
+
+#endif // CONTENT_COMMON_INPUT_INPUT_EVENT_H_