Revert of Remove about:srcdoc url conversion.

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 281 matching lines @@
   // Timestamp at which the UI action that triggered the navigation originated.
   IPC_STRUCT_MEMBER(base::TimeTicks, ui_timestamp)
 
   // The insecure request policy the document for the load is enforcing.
   IPC_STRUCT_MEMBER(blink::WebInsecureRequestPolicy, insecure_request_policy)
 
   // True if the document for the load is a unique origin that should be
   // considered potentially trustworthy.
   IPC_STRUCT_MEMBER(bool, has_potentially_trustworthy_unique_origin)
 
+  // True if the navigation originated as an srcdoc attribute.
+  IPC_STRUCT_MEMBER(bool, is_srcdoc)
+
   // See WebSearchableFormData for a description of these.
   // Not used by PlzNavigate: in that case these fields are sent to the browser
   // in BeginNavigationParams.
   IPC_STRUCT_MEMBER(GURL, searchable_form_url)
   IPC_STRUCT_MEMBER(std::string, searchable_form_encoding)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(FrameMsg_PostMessage_Params)
   // Whether the data format is supplied as serialized script value, or as
   // a simple string. If it is a raw string, must be converted from string to a
@@ skipping 1224 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.