PaintChunk::id

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

Index: third_party/WebKit/Source/platform/graphics/paint/ScopedPaintChunkProperties.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/ScopedPaintChunkProperties.h b/third_party/WebKit/Source/platform/graphics/paint/ScopedPaintChunkProperties.h
index ec105314abfd10f60cde85aa1b90a83bfd0986cc..464f71c693394b5a871ab1312ebbddd00b7e92dc 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/ScopedPaintChunkProperties.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/ScopedPaintChunkProperties.h
@@ -5,6 +5,8 @@
 #ifndef ScopedPaintChunkProperties_h
 #define ScopedPaintChunkProperties_h
 
+#include "platform/graphics/paint/DisplayItem.h"
+#include "platform/graphics/paint/PaintChunk.h"
 #include "platform/graphics/paint/PaintChunkProperties.h"
 #include "platform/graphics/paint/PaintController.h"
 #include "wtf/Allocator.h"
@@ -16,16 +18,27 @@ class ScopedPaintChunkProperties {
     DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
     WTF_MAKE_NONCOPYABLE(ScopedPaintChunkProperties);
 public:
-    ScopedPaintChunkProperties(PaintController& paintController, const PaintChunkProperties& properties)
+    ScopedPaintChunkProperties(PaintController& paintController, const DisplayItemClient& client, DisplayItem::Type type, const PaintChunkProperties& properties)
         : m_paintController(paintController)
         , m_previousProperties(paintController.currentPaintChunkProperties())
     {
-        m_paintController.updateCurrentPaintChunkProperties(properties);
+        PaintChunk::Id id(client, type);
+        m_paintController.updateCurrentPaintChunkProperties(&id, properties);
     }
 
+    // Omits the type parameter, in case that the client creates only one PaintChunkProperties node during each painting.
+    ScopedPaintChunkProperties(PaintController& paintController, const DisplayItemClient& client, const PaintChunkProperties& properties)
+        : ScopedPaintChunkProperties(paintController, client, DisplayItem::UninitializedType, properties)
+    { }
+
     ~ScopedPaintChunkProperties()
     {
-        m_paintController.updateCurrentPaintChunkProperties(m_previousProperties);
+        // We should not return to the previous id, because that may cause a new chunk to use
+        // the same id as that of the previous chunk before this ScopedPaintChunkProperties.
+        // The painter should create another scope of paint properties with new id, or the
+        // new chunk will have no id and will not match any old chunk and will be treated as
+        // fully invalidated for rasterization.
+        m_paintController.updateCurrentPaintChunkProperties(nullptr, m_previousProperties);
     }
 
 private: