Avoid mutating frame unique name after first real commit.

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 5742191df101fb60dd771901f535fb76bb6c1d27..a159fa79dae11044d36c7fe500345db4e90a212e 100644
--- a/third_party/WebKit/Source/core/page/FrameTree.cpp
+++ b/third_party/WebKit/Source/core/page/FrameTree.cpp
@@ -73,6 +73,14 @@ void FrameTree::setName(const AtomicString& name)
 
     m_name = name;
 
+    // https://crbug.com/607205: Make sure m_uniqueName doesn't change after
+    // initial navigation - session history depends on this.
+    if (m_thisFrame->isLocalFrame()) {

[dcheng, 2016/09/07 19:54:13]

This check is redundant (see the DCHECK on line 59 =)

[Łukasz Anforowicz, 2016/09/09 16:21:38]

Done.

+        LocalFrame* localFrame = toLocalFrame(m_thisFrame);
+        if (localFrame->loader().stateMachine()->committedFirstRealDocumentLoad())
+            return;
+    }
+
     // Remove our old frame name so it's not considered in calculateUniqueNameForChildFrame
     // and appendUniqueSuffix calls below.
     m_uniqueName = AtomicString();