Handle removed display items in under-invalidation checking in cached subsequences

third_party/WebKit/Source/platform/graphics/paint/PaintController.h

 // Copyright 2014 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.
 
 #ifndef PaintController_h
 #define PaintController_h
 
 #include "platform/PlatformExport.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/IntRect.h"
@@ skipping 157 matching lines @@
 #if DCHECK_IS_ON()
         , m_numSequentialMatches(0)
         , m_numOutOfOrderMatches(0)
         , m_numIndexedItems(0)
 #endif
     {
         resetCurrentListIndices();
     }
 
 private:
-    friend class PaintControllerTest;
+    friend class PaintControllerTestBase;
     friend class PaintControllerPaintTestBase;
 
     void ensureNewDisplayItemListInitialCapacity()
     {
         if (m_newDisplayItemList.isEmpty()) {
             // TODO(wangxianzhu): Consider revisiting this heuristic.
             m_newDisplayItemList = DisplayItemList(m_currentPaintArtifact.getDisplayItemList().isEmpty() ? kInitialDisplayItemListCapacityBytes : m_currentPaintArtifact.getDisplayItemList().usedCapacityInBytes());
         }
     }
 
@@ skipping 16 matching lines @@
     void copyCachedSubsequence(size_t&);
 
     // Resets the indices (e.g. m_nextItemToMatch) of m_currentPaintArtifact.getDisplayItemList()
     // to their initial values. This should be called when the DisplayItemList in m_currentPaintArtifact
     // is newly created, or is changed causing the previous indices to be invalid.
     void resetCurrentListIndices();
 
 #if DCHECK_IS_ON()
     // The following two methods are for checking under-invalidations
     // (when RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled).
-    void showUnderInvalidationError(const char* reason, const DisplayItem& newItem, const DisplayItem& oldItem) const;
+    void showUnderInvalidationError(const char* reason, const DisplayItem& newItem, const DisplayItem* oldItem) const;
     void checkUnderInvalidation();
     bool isCheckingUnderInvalidation() const { return m_underInvalidationCheckingEnd - m_underInvalidationCheckingBegin > 0; }
 #endif
 
     // The last complete paint artifact.
     // In SPv2, this includes paint chunks as well as display items.
     PaintArtifact m_currentPaintArtifact;
 
     // Data being used to build the next paint artifact.
     DisplayItemList m_newDisplayItemList;
@@ skipping 38 matching lines @@
     // This is used to check duplicated ids during createAndAppend().
     DisplayItemIndicesByClientMap m_newDisplayItemIndicesByClient;
 
     // These are set in useCachedDrawingIfPossible() and useCachedSubsequenceIfPossible()
     // when we could use cached drawing or subsequence and under-invalidation checking is on,
     // indicating the begin and end of the cached drawing or subsequence in the current list.
     // The functions return false to let the client do actual painting, and PaintController
     // will check if the actual painting results are the same as the cached.
     size_t m_underInvalidationCheckingBegin;
     size_t m_underInvalidationCheckingEnd;
+    // Number of probable under-invalidations that have been skipped temporarily because the
+    // mismatching display items may be removed in the future because of no-op pairs or
+    // compositing folding.
+    int m_skippedProbableUnderInvalidationCount;
     String m_underInvalidationMessagePrefix;
 #endif
 
 #if CHECK_DISPLAY_ITEM_CLIENT_ALIVENESS
     // A stack recording subsequence clients that are currently painting.
     Vector<const DisplayItemClient*> m_currentSubsequenceClients;
 #endif
 };
 
 } // namespace blink
 
 #endif // PaintController_h