Replicating WebFrame::uniqueName across renderers.

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

Index: third_party/WebKit/Source/core/page/FrameTree.cpp
diff --git a/third_party/WebKit/Source/core/page/FrameTree.cpp b/third_party/WebKit/Source/core/page/FrameTree.cpp
index a4816ad06203d02d9e3da21a00efa598bef03ea6..137818292e05459b6a3b480bbe0570a0a001a628 100644
--- a/third_party/WebKit/Source/core/page/FrameTree.cpp
+++ b/third_party/WebKit/Source/core/page/FrameTree.cpp
@@ -58,12 +58,21 @@ void FrameTree::setName(const AtomicString& name, const AtomicString& fallbackNa
         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::setPrecalculatedName(const AtomicString& name, const AtomicString& uniqueName)
 {
+    if (!parent()) {
+        ASSERT(uniqueName == name);
+    } else {
+        ASSERT(!uniqueName.isEmpty());
+    }
+
     m_name = name;
     m_uniqueName = uniqueName;
 }
@@ -123,8 +132,19 @@ bool FrameTree::uniqueNameExists(const AtomicString& name) const
     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& name,
+    const AtomicString& fallbackName) const
 {
+    const AtomicString& requestedName = name.isEmpty() ? fallbackName : name;
     if (!requestedName.isEmpty() && !uniqueNameExists(requestedName) && requestedName != "_blank")
         return requestedName;
 
@@ -147,23 +167,23 @@ AtomicString FrameTree::uniqueChildName(const AtomicString& requestedName) const
             break;
         chain.append(frame);
     }
-    StringBuilder name;
-    name.append(framePathPrefix);
+    StringBuilder uniqueName;
+    uniqueName.append(framePathPrefix);
     if (frame) {
-        name.append(frame->tree().uniqueName().string().substring(framePathPrefixLength,
+        uniqueName.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());
+        uniqueName.append('/');
+        uniqueName.append(frame->tree().uniqueName());
     }
 
-    name.appendLiteral("/<!--frame");
-    name.appendNumber(childCount() - 1);
-    name.appendLiteral("-->-->");
+    uniqueName.appendLiteral("/<!--frame");
+    uniqueName.appendNumber(childCount() - (existingChildFrame ? 1 : 0));
+    uniqueName.appendLiteral("-->-->");
 
-    return name.toAtomicString();
+    return uniqueName.toAtomicString();
 }
 
 Frame* FrameTree::scopedChild(unsigned index) const