Add WebDragData to blink::WebView::dragtargetDrop

content/common/drag_messages.h

 // Copyright (c) 2012 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.
 
 // IPC messages for drag and drop.
 // Multiply-included message file, hence no include guard.
 
+#include <vector>
+
+#include "base/strings/string16.h"

[dcheng, 2016/05/24 05:51:50]

This include isn't needed anymore.

[hush (inactive), 2016/05/24 20:26:09]

Done. 
And... is there a tool that tells me which includes are not needed?

[dcheng, 2016/05/25 00:07:57]

Sadly there is not.

 #include "content/common/drag_event_source_info.h"
 #include "content/public/common/drop_data.h"
 #include "ipc/ipc_message_macros.h"
 #include "third_party/WebKit/public/platform/WebDragOperation.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/vector2d.h"
 
 #define IPC_MESSAGE_START DragMsgStart
 
 // Messages sent from the browser to the renderer.
 
 IPC_MESSAGE_ROUTED5(DragMsg_TargetDragEnter,
-                    content::DropData /* drop_data */,
+                    std::vector<content::DropData::MetaData> /* drop_data */,
                     gfx::Point /* client_pt */,
                     gfx::Point /* screen_pt */,
                     blink::WebDragOperationsMask /* ops_allowed */,
                     int /* key_modifiers */)
 
 IPC_MESSAGE_ROUTED4(DragMsg_TargetDragOver,
                     gfx::Point /* client_pt */,
                     gfx::Point /* screen_pt */,
                     blink::WebDragOperationsMask /* ops_allowed */,
                     int /* key_modifiers */)
 
 IPC_MESSAGE_ROUTED0(DragMsg_TargetDragLeave)
 
-IPC_MESSAGE_ROUTED3(DragMsg_TargetDrop,
+IPC_MESSAGE_ROUTED4(DragMsg_TargetDrop,
+                    content::DropData /* drop_data */,
                     gfx::Point /* client_pt */,
                     gfx::Point /* screen_pt */,
                     int /* key_modifiers */)
 
 // Notifies the renderer when and where the mouse-drag ended.
 IPC_MESSAGE_ROUTED3(DragMsg_SourceEnded,
                     gfx::Point /* client_pt */,
                     gfx::Point /* screen_pt */,
                     blink::WebDragOperation /* drag_operation */)
 
@@ skipping 10 matching lines @@
                     content::DropData /* drop_data */,
                     blink::WebDragOperationsMask /* ops_allowed */,
                     SkBitmap /* image */,
                     gfx::Vector2d /* image_offset */,
                     content::DragEventSourceInfo /* event_info */)
 
 // The page wants to update the mouse cursor during a drag & drop operation.
 // |is_drop_target| is true if the mouse is over a valid drop target.
 IPC_MESSAGE_ROUTED1(DragHostMsg_UpdateDragCursor,
                     blink::WebDragOperation /* drag_operation */)