Intersection Observer support for OOPIF

content/common/frame_messages.h

 // Copyright 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.
 
 // IPC messages for interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1263 matching lines @@
 // Forwards an input event to a child.
 // TODO(nick): Temporary bridge, revisit once the browser process can route
 // input directly to subframes. http://crbug.com/339659
 IPC_MESSAGE_ROUTED1(FrameHostMsg_ForwardInputEvent,
                     IPC::WebInputEventPointer /* event */)
 
 // Tells the parent that a child's frame rect has changed (or the rect/scroll
 // position of a child's ancestor has changed).
 IPC_MESSAGE_ROUTED1(FrameHostMsg_FrameRectChanged, gfx::Rect /* frame_rect */)
 
+// Sent by a parent frame to update its child's viewport intersection rect for
+// use by the IntersectionObserver API.
+IPC_MESSAGE_ROUTED2(FrameHostMsg_UpdateViewportIntersection,
+                    gfx::Rect /* viewport_intersection */,
+                    gfx::Point /* root_offset */)
+
 // Informs the child that the frame has changed visibility.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_VisibilityChanged, bool /* visible */)
 
 // Used to tell the parent that the user right clicked on an area of the
 // content area, and a context menu should be shown for it. The params
 // object contains information about the node(s) that were selected when the
 // user right clicked.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_ContextMenu, content::ContextMenuParams)
 
 // Notification that the text selection has changed.
@@ skipping 211 matching lines @@
 // nearest find result in the sending frame.
 IPC_MESSAGE_ROUTED2(FrameHostMsg_GetNearestFindResult_Reply,
                     int /* nfr_request_id */,
                     float /* distance */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent FrameMsg, then ifdefs for platform specific FrameMsg, then
 // platform independent FrameHostMsg, then ifdefs for platform specific
 // FrameHostMsg.