Replicating WebFrame::uniqueName across renderers.

content/common/frame_replication_state.h

 // Copyright 2014 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_FRAME_REPLICATION_STATE_H_
 #define CONTENT_COMMON_FRAME_REPLICATION_STATE_H_
 
 #include "content/common/content_export.h"
 #include "url/origin.h"
 
 namespace blink {
 enum class WebTreeScopeType;
 enum class WebSandboxFlags;
 }
 
 namespace content {
 
 // This structure holds information that needs to be replicated between a
 // RenderFrame and any of its associated RenderFrameProxies.
 struct CONTENT_EXPORT FrameReplicationState {
   FrameReplicationState();
   FrameReplicationState(blink::WebTreeScopeType scope,
                         const std::string& name,
+                        const std::string& unique_name,
                         blink::WebSandboxFlags sandbox_flags,
                         bool should_enforce_strict_mixed_content_checking);
   ~FrameReplicationState();
 
   // Current origin of the frame. This field is updated whenever a frame
   // navigation commits.
   //
   // TODO(alexmos): For now, |origin| updates are immediately sent to all frame
   // proxies when in --site-per-process mode. This isn't ideal, since Blink
   // typically needs a proxy's origin only when performing security checks on
@@ skipping 10 matching lines @@
   //
   // When a parent frame updates an <iframe>'s sandbox attribute via
   // JavaScript, |sandbox_flags| are updated only after the child frame commits
   // a navigation that makes the updated flags take effect.  This is also the
   // point at which updates are sent to proxies (see
   // CommitPendingSandboxFlags()). The proxies need updated flags so that they
   // can be inherited properly if a proxy ever becomes a parent of a local
   // frame.
   blink::WebSandboxFlags sandbox_flags;
 
-  // The assigned name of the frame. This name can be empty, unlike the unique
-  // name generated internally in the DOM tree.
+  // The assigned name of the frame (see WebFrame::assignedName()).
   //
   // |name| is set when a new child frame is created using the value of the
   // <iframe> element's "name" attribute (see
   // RenderFrameHostImpl::OnCreateChildFrame), and it is updated dynamically
   // whenever a frame sets its window.name.
   //
   // |name| updates are immediately sent to all frame proxies (when in
   // --site-per-process mode), so that other frames can look up or navigate a
   // frame using its updated name (e.g., using window.open(url, frame_name)).
   std::string name;
 
+  // Unique name of the frame (see WebFrame::uniqueName()).
+  //
+  // |unique_name| is used in heuristics that try to identify the same frame
+  // across different, unrelated navigations (i.e. to refer to the frame
+  // when going back/forward in session history OR when refering to the frame
+  // in layout tests results).
+  //
+  // |unique_name| needs to be replicated to ensure that unique name for a given
+  // frame is the same across all renderers - without replication a renderer
+  // might arrive at a different value when recalculating the unique name from
+  // scratch.
+  std::string unique_name;
+
   // Whether the frame is in a document tree or a shadow tree, per the Shadow
   // DOM spec: https://w3c.github.io/webcomponents/spec/shadow/
   // Note: This should really be const, as it can never change once a frame is
   // created. However, making it const makes it a pain to embed into IPC message
   // params: having a const member implicitly deletes the copy assignment
   // operator.
   blink::WebTreeScopeType scope;
 
   // True if a frame's current document should strictly block all mixed
   // content. Updates are immediately sent to all frame proxies when
   // frames live in different processes.
   bool should_enforce_strict_mixed_content_checking;
 
   // TODO(alexmos): Eventually, this structure can also hold other state that
   // needs to be replicated, such as frame sizing info.
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_FRAME_REPLICATION_STATE_H_