FrameLoader: remove a TODO and add a comment

Remove a TODO that I left before because I confirmed that
current code is correct, and chaging it makes many unit tests
fail.

BUG=670232

Review-Url: https://codereview.chromium.org/2587323002
Cr-Commit-Position: refs/heads/master@{#439807}

third_party/WebKit/Source/core/loader/FrameLoader.cpp

@@ -122,8 +122,7 @@ bool isReloadLoadType(FrameLoadType type) {
 }
 
 static bool needsHistoryItemRestore(FrameLoadType type) {
-  // TODO(toyoshim): Shall we return true for FrameLoadTypeInitialHistoryLoad
-  // too?
+  // FrameLoadtypeInitialHistoryLoad is intentionally excluded.
   return type == FrameLoadTypeBackForward || isReloadLoadType(type);
 }