Replicating WebFrame::uniqueName across renderers.

third_party/WebKit/Source/core/page/FrameTree.cpp

 /*
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 40 matching lines @@
 {
 }
 
 void FrameTree::setName(const AtomicString& name, const AtomicString& fallbackName)
 {
     m_name = name;
     if (!parent()) {
         m_uniqueName = name;
         return;
     }
-    m_uniqueName = AtomicString(); // Remove our old frame name so it's not considered in uniqueChildName.
-    m_uniqueName = parent()->tree().uniqueChildName(name.isEmpty() ? fallbackName : name);
+
+    // Remove our old frame name so it's not considered in calculateUniqueNameForChildFrame.
+    m_uniqueName = AtomicString();
+
+    m_uniqueName = parent()->tree().calculateUniqueNameForChildFrame(true, name, fallbackName);
 }
 
-void FrameTree::setNameForReplacementFrame(const AtomicString& name, const AtomicString& uniqueName)
+void FrameTree::setReplicatedName(const AtomicString& name, const AtomicString& uniqueName)
 {
+    if (!parent()) {
+        ASSERT(uniqueName == name);
+    } else {
+        ASSERT(!uniqueName.isEmpty());
+    }
+
     m_name = name;
     m_uniqueName = uniqueName;
 }
 
 Frame* FrameTree::parent() const
 {
     if (!m_thisFrame->client())
         return nullptr;
     return m_thisFrame->client()->parent();
 }
@@ skipping 39 matching lines @@
 
 bool FrameTree::uniqueNameExists(const AtomicString& name) const
 {
     for (Frame* frame = top(); frame; frame = frame->tree().traverseNext()) {
         if (frame->tree().uniqueName() == name)
             return true;
     }
     return false;
 }
 
-AtomicString FrameTree::uniqueChildName(const AtomicString& requestedName) const
+AtomicString FrameTree::calculateUniqueNameForNewChildFrame(
+    const AtomicString& name,
+    const AtomicString& fallbackName) const
 {
+    return calculateUniqueNameForChildFrame(false, name, fallbackName);
+}
+
+AtomicString FrameTree::calculateUniqueNameForChildFrame(
+    bool existingChildFrame,
+    const AtomicString& originalRequestedName,
+    const AtomicString& fallbackName) const
+{
+    const AtomicString& requestedName =
+        originalRequestedName.isEmpty() ? fallbackName : originalRequestedName;
     if (!requestedName.isEmpty() && !uniqueNameExists(requestedName) && requestedName != "_blank")
         return requestedName;
 
     // Create a repeatable name for a child about to be added to us. The name must be
     // unique within the frame tree. The string we generate includes a "path" of names
     // from the root frame down to us. For this path to be unique, each set of siblings must
     // contribute a unique name to the path, which can't collide with any HTML-assigned names.
     // We generate this path component by index in the child list along with an unlikely
     // frame name that can't be set in HTML because it collides with comment syntax.
 
@@ skipping 15 matching lines @@
         name.append(frame->tree().uniqueName().string().substring(framePathPrefixLength,
             frame->tree().uniqueName().length() - framePathPrefixLength - framePathSuffixLength));
     }
     for (int i = chain.size() - 1; i >= 0; --i) {
         frame = chain[i];
         name.append('/');
         name.append(frame->tree().uniqueName());
     }
 
     name.appendLiteral("/<!--frame");
-    name.appendNumber(childCount() - 1);
+    name.appendNumber(childCount() - (existingChildFrame ? 1 : 0));

[dcheng, 2016/02/16 22:17:29]

Is it possible to pull the FrameTree changes into a separate patch?

[Łukasz Anforowicz, 2016/02/16 23:39:53]

I think it is not possible.

1. I've added propagation of |uniqueName| wherever |name| was propagated - this
covers WebFrameClient::createChildFrame.

2. (1) requires that WebLocalFrameImpl::initializeCoreFrame knows the
|uniqueName| before calling WebFrameClient::createChildFrame - the |uniqueName|
is provided by a new FrameTree::calculateUniqueNameForNewChildFrame method.

3. The child frame has not yet been created and added to the parent frame at the
time when FrameTree::calculateUniqueNameForNewChildFrame method is called from
WebLocalFrameImpl::initializeCoreFrame.  This means that
FrameTree::calculateUniqueNameForChildFrame has to adjust childCount()-based
calculations depending on how it is called (for new vs for existing child
frame).

     name.appendLiteral("-->-->");
 
     return name.toAtomicString();
 }
 
 Frame* FrameTree::scopedChild(unsigned index) const
 {
     unsigned scopedIndex = 0;
     for (Frame* child = firstChild(); child; child = child->tree().nextSibling()) {
         if (child->client()->inShadowTree())
@@ skipping 228 matching lines @@
 {
     if (!frame) {
         printf("Null input frame\n");
         return;
     }
 
     printFrames(frame->tree().top(), frame, 0);
 }
 
 #endif