Replicating WebFrame::uniqueName across renderers.

content/common/frame_replication_state.h

Index: content/common/frame_replication_state.h
diff --git a/content/common/frame_replication_state.h b/content/common/frame_replication_state.h
index 414bc3c130412e48dab34aeee29025e85600f9ef..9014241b765001aaf454b5b108d30355b24e85c9 100644
--- a/content/common/frame_replication_state.h
+++ b/content/common/frame_replication_state.h
@@ -21,6 +21,7 @@ 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();
@@ -51,8 +52,7 @@ struct CONTENT_EXPORT FrameReplicationState {
   // 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.
   //
   // |name| is set when a new child frame is created using the value of the
   // <iframe> element's "name" attribute (see
@@ -64,6 +64,9 @@ struct CONTENT_EXPORT FrameReplicationState {
   // frame using its updated name (e.g., using window.open(url, frame_name)).
   std::string name;
 
+  // Unique name of the frame.

[alexmos, 2016/02/10 00:46:46]

Maybe also mention what it's for, why it's replicated, and that its updates are
tied to |name| updates?

[Łukasz Anforowicz, 2016/02/10 22:10:51]

I've expanded the comment:
1) added a reference to WebFrame::uniqueName
2) explained how unique name is used
3) explained why we need to replicate.

I didn't add explanation that updates of |unique_name| are tied to |name|
updates - this seems like an implementation detail that can change (right?) and
therefore I think we should avoid putting this into a comment (because it can
become stale and misleading).

+  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