DCHECK that paint properties are never null

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

Index: third_party/WebKit/Source/platform/graphics/paint/PaintChunker.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PaintChunker.h b/third_party/WebKit/Source/platform/graphics/paint/PaintChunker.h
index c96a059e62acd72e0fb280d7981c8876c03af24e..acf1558d740c5802e7738f94d8969b15be51bbfa 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintChunker.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintChunker.h
@@ -10,6 +10,7 @@
 #include "platform/graphics/paint/PaintChunk.h"
 #include "platform/graphics/paint/PaintChunkProperties.h"
 #include "wtf/Allocator.h"
+#include "wtf/AutoReset.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/Vector.h"
 
@@ -74,6 +75,19 @@ class PLATFORM_EXPORT PaintChunker final {
   PaintChunkProperties m_currentProperties;
 };
 
+#if DCHECK_IS_ON()
+class DisableNullPaintPropertyChecks {
+  STACK_ALLOCATED();
+  WTF_MAKE_NONCOPYABLE(DisableNullPaintPropertyChecks);
+
+ public:
+  DisableNullPaintPropertyChecks();
+
+ private:
+  AutoReset<bool> m_disabler;
+};
+#endif  // DCHECK_IS_ON()
+
 }  // namespace blink
 
 #endif  // PaintChunker_h