Disable subsequence caching when didLayoutWithPendingStylesheets is true.

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #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"
 #include "web/tests/sim/SimRequest.h"
 #include "web/tests/sim/SimTest.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
@@ skipping 246 matching lines @@
     // script that touched offsetTop in the child frame.
     auto* childFrame = toHTMLIFrameElement(document().getElementById("frame"));
     childFrame->contentDocument()->updateLayoutIgnorePendingStylesheets();
 
     auto frame2 = compositor().beginFrame();
 
     // The child frame still has pending sheets, and the parent frame has no
     // 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).
     // TODO(esprehn): Why FOUC the background (borders, etc.) of iframes and
     // composited layers? Seems like a bug.
     EXPECT_EQ(3, frame2.drawCount());
     EXPECT_TRUE(frame2.contains(SimCanvas::Rect, "white"));
     EXPECT_TRUE(frame2.contains(SimCanvas::Rect, "pink"));
     EXPECT_TRUE(frame2.contains(SimCanvas::Rect, "green"));
 
     // Finish loading the sheets in the child frame. After it should issue a
     // paint invalidation for every layer since frame2 painted them but skipped
     // painting the real content to avoid FOUC.
     cssResource.complete();
 
     // First frame where all frames are loaded, should paint the text in the
     // child frame.
     auto frame3 = compositor().beginFrame();
     EXPECT_TRUE(frame3.containsText());
 }
 
 } // namespace blink