Always report maybe-clipped when painting fragmented content

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

 // 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.
 
 #include "platform/graphics/paint/PaintController.h"
 
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/graphics/paint/DrawingDisplayItem.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
 #include "platform/wtf/AutoReset.h"
@@ skipping 434 matching lines @@
   AutoReset<size_t> subsequence_begin_index(
       &current_cached_subsequence_begin_index_in_new_list_,
       new_display_item_list_.size());
   DisplayItem* cached_item =
       &current_paint_artifact_.GetDisplayItemList()[begin_index];
 
   if (RuntimeEnabledFeatures::paintUnderInvalidationCheckingEnabled()) {
     DCHECK(!IsCheckingUnderInvalidation());
     under_invalidation_checking_begin_ = begin_index;
     under_invalidation_message_prefix_ =
-        "(In cached subsequence of " + cached_item->Client().DebugName() + ")";
+        "(In cached subsequence starting with " +
+        cached_item->Client().DebugName() + ")";
   }
 
   Vector<PaintChunk>::const_iterator cached_chunk;
   if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
     cached_chunk =
         current_paint_artifact_.FindChunkByDisplayItemIndex(begin_index);
     DCHECK(cached_chunk != current_paint_artifact_.PaintChunks().end());
     UpdateCurrentPaintChunkProperties(
         cached_chunk->id ? &*cached_chunk->id : nullptr,
         cached_chunk->properties);
@@ skipping 466 matching lines @@
               show_paint_records
                   ? (DisplayItemList::JsonOptions::kShowPaintRecords |
                      DisplayItemList::JsonOptions::kShowClientDebugName)
                   : DisplayItemList::JsonOptions::kShowClientDebugName)
           ->ToPrettyJSONString()
           .Utf8()
           .Data());
 }
 
 }  // namespace blink