OOPIF: Handle cross-site frames being blocked by X-Frame-Options or CSP.

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 828 matching lines @@
 // Serialize target frame and its resources into MHTML and write it into the
 // provided destination file handle.  Note that when serializing multiple
 // frames, one needs to serialize the *main* frame first (the main frame
 // needs to go first according to RFC2557 + the main frame will trigger
 // generation of the MHTML header).
 IPC_MESSAGE_ROUTED1(FrameMsg_SerializeAsMHTML, FrameMsg_SerializeAsMHTML_Params)
 
 IPC_MESSAGE_ROUTED1(FrameMsg_SetFrameOwnerProperties,
                     blink::WebFrameOwnerProperties /* frame_owner_properties */)
 
+// Notifies the frame that its load was blocked by X-Frame-Options or CSP
+// frame-ancestors while loading.
+IPC_MESSAGE_ROUTED0(FrameMsg_CancelLoadAfterXFrameOptionsOrCSPDenied)

[Charlie Reis, 2016/02/26 01:13:22]

Is there a reason to make this specific to these features?  I'm wondering if
there's a more general "blocked load" concept that this might cover.

[alexmos, 2016/02/26 02:38:05]

Good question.  It's only specific in the sense that we do some special stuff in
the parent frame (that the spec requires) so that it can't determine whether the
child was blocked or not (i.e., dispatch the load event on the iframe element,
change the blocked frame's origin to unique).  I don't know of anything else
besides XFO+CSP that needs this at the moment, but there might be other kinds of
blocked loads in the future that might reuse this (e.g., clickjacking
protection), so maybe this whole plumbing should be renamed to 
FrameMsg_BlockedLoad, etc.  WDYT?  I really like that this would simplify all
the names. :)

[Charlie Reis, 2016/02/26 21:10:01]

Yeah, let's make it BlockedLoad, with documentation about all the things it does
(and the motivation).  That should make it a bit easier to follow, and possibly
easier to reuse later.

+
 // Request to continue running the sequential focus navigation algorithm in
 // this frame.  |source_routing_id| identifies the frame that issued this
 // request.  This message is sent when pressing <tab> or <shift-tab> needs to
 // find the next focusable element in a cross-process frame.
 IPC_MESSAGE_ROUTED2(FrameMsg_AdvanceFocus,
                     blink::WebFocusType /* type */,
                     int32_t /* source_routing_id */)
 
 // Sent when the user wants to search for a word on the page (find-in-page).
 IPC_MESSAGE_ROUTED3(FrameMsg_Find,
@@ skipping 129 matching lines @@
 IPC_MESSAGE_ROUTED2(FrameHostMsg_DidChangeSandboxFlags,
                     int32_t /* subframe_routing_id */,
                     blink::WebSandboxFlags /* updated_flags */)
 
 // Notifies the browser that frame owner properties have changed for a subframe
 // of this frame.
 IPC_MESSAGE_ROUTED2(FrameHostMsg_DidChangeFrameOwnerProperties,
                     int32_t /* subframe_routing_id */,
                     blink::WebFrameOwnerProperties /* frame_owner_properties */)
 
+// Notifies the browser process that a subframe was blocked by
+// X-Frame-Options or CSP frame-ancestors while loading.
+//
+// TODO(mkwst, alexmos): This will become unnecessary once X-Frame-Options and
+// CSP enforcement moves to the browser process (https://crbug.com/555418).
+IPC_MESSAGE_ROUTED0(FrameHostMsg_DidCancelLoadAfterXFrameOptionsOrCSPDenied)
+
 // Changes the title for the page in the UI when the page is navigated or the
 // title changes. Sent for top-level frames.
 IPC_MESSAGE_ROUTED2(FrameHostMsg_UpdateTitle,
                     base::string16 /* title */,
                     blink::WebTextDirection /* title direction */)
 
 // Change the encoding name of the page in UI when the page has detected
 // proper encoding name. Sent for top-level frames.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_UpdateEncoding,
                     std::string /* new encoding name */)
@@ skipping 430 matching lines @@
 IPC_MESSAGE_ROUTED3(FrameHostMsg_FindMatchRects_Reply,
                     int /* version */,
                     std::vector<gfx::RectF> /* rects */,
                     gfx::RectF /* active_rect */)
 #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.