Don't reuse HistoryItems for multiple navigations

Source/web/tests/ProgrammaticScrollTest.cpp

Index: Source/web/tests/ProgrammaticScrollTest.cpp
diff --git a/Source/web/tests/ProgrammaticScrollTest.cpp b/Source/web/tests/ProgrammaticScrollTest.cpp
index 08320f4dbb7922cce358b94291ddb597f9796d26..81c16af4f5ab63b462778ec76fe26779bfbefa05 100644
--- a/Source/web/tests/ProgrammaticScrollTest.cpp
+++ b/Source/web/tests/ProgrammaticScrollTest.cpp
@@ -92,10 +92,10 @@ TEST_F(ProgrammaticScrollTest, RestoreScrollPositionAndViewStateWithoutScale)
     webViewImpl->setPageScaleFactor(3.0f);
     webViewImpl->setMainFrameScrollOffset(WebPoint(0, 500));
     frame->view()->setWasScrolledByUser(false);
-    frame->loader().currentItem()->setPageScaleFactor(0);
+    frame->loader().currentItem()->setPageScaleFactor(1.0f);
     frame->loader().currentItem()->setScrollPoint(WebPoint(0, 400));
 
-    // FrameLoader::restoreScrollPositionAndViewState flows differently if scale is zero.
+    // FrameLoader::restoreScrollPositionAndViewState flows differently if scale is 1.
     frame->loader().restoreScrollPositionAndViewState();
 
     // Expect that only the scroll position was restored.