Disable subsequence caching when didLayoutWithPendingStylesheets is true.

third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp

Index: third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp b/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp
index db54b4ac706c7fb35be0bdb33f05bf7093fa3e6c..a6071be22e165ff3596799225ba3f5443a4ba51b 100644
--- a/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp
+++ b/third_party/WebKit/Source/web/tests/DocumentLoadingRenderingTest.cpp
@@ -4,6 +4,8 @@
 
 #include "core/dom/Document.h"
 #include "core/html/HTMLIFrameElement.h"
+#include "core/layout/LayoutView.h"
+#include "core/paint/PaintLayer.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "web/tests/sim/SimCompositor.h"
 #include "web/tests/sim/SimDisplayItemList.h"
@@ -270,6 +272,14 @@ TEST_F(DocumentLoadingRenderingTest, ShouldNotPaintIframeContentWithPendingSheet
     // invalid paint so we shouldn't draw any text.
     EXPECT_FALSE(frame2.containsText());
 
+    LayoutView* iframeLayoutView = childFrame->contentDocument()->layoutView();
+    const DisplayItemList& displayItemList = iframeLayoutView->layer()->graphicsLayerBacking()->getPaintController().getDisplayItemList();
+    // Check that the DisplayItemList has no subsequene caching markers. These are not allowed in pending-style-sheets mode
+    // since otherwise caching would be incorrect.
+    ASSERT_EQ(2u, displayItemList.size());
+    EXPECT_EQ(DisplayItem::DocumentBackground, displayItemList[0].getType());
+    EXPECT_EQ(DisplayItem::BoxDecorationBackground, displayItemList[1].getType());
+
     // 1 for the main frame background (white),
     // 1 for the iframe background (pink)
     // 1 for the composited transform layer in the iframe (green).