Revert of Client side display item cache flag

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

Index: third_party/WebKit/Source/platform/graphics/paint/PaintController.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PaintController.h b/third_party/WebKit/Source/platform/graphics/paint/PaintController.h
index eda39ff41e03e75780a895899090a8b53065cbcf..b9edbba2ab4b43aae356535d4854d61c6f3537ed 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintController.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintController.h
@@ -163,6 +163,15 @@
         return m_trackedPaintInvalidationObjects ? *m_trackedPaintInvalidationObjects : Vector<String>();
     }
 
+    bool clientHasCheckedPaintInvalidation(const DisplayItemClient& client) const
+    {
+        return m_clientsCheckedPaintInvalidation.contains(&client);
+    }
+    void setClientHasCheckedPaintInvalidation(const DisplayItemClient& client)
+    {
+        m_clientsCheckedPaintInvalidation.add(&client);
+    }
+
 #if ENABLE(ASSERT)
     void assertDisplayItemClientsAreLive();
 #endif
@@ -170,18 +179,20 @@
 protected:
     PaintController()
         : m_newDisplayItemList(kInitialDisplayItemListCapacityBytes)
+        , m_validlyCachedClientsDirty(false)
         , m_constructionDisabled(false)
         , m_subsequenceCachingDisabled(false)
         , m_textPainted(false)
         , m_imagePainted(false)
         , m_skippingCacheCount(0)
         , m_numCachedNewItems(0)
-        , m_nextScope(1)
-    { }
+        , m_nextScope(1) { }
 
 private:
     // Set new item state (scopes, cache skipping, etc) for a new item.
     void processNewItem(DisplayItem&);
+
+    void updateValidlyCachedClientsIfNeeded() const;
 
 #ifndef NDEBUG
     WTF::String displayItemListAsDebugString(const DisplayItemList&) const;
@@ -209,8 +220,6 @@
 
     void commitNewDisplayItemsInternal(const LayoutSize& offsetFromLayoutObject);
 
-    void updateCacheGeneration();
-
     // The last complete paint artifact.
     // In SPv2, this includes paint chunks as well as display items.
     PaintArtifact m_currentPaintArtifact;
@@ -218,6 +227,18 @@
     // Data being used to build the next paint artifact.
     DisplayItemList m_newDisplayItemList;
     PaintChunker m_newPaintChunks;
+
+    // Contains all clients having valid cached paintings if updated.
+    // It's lazily updated in updateValidlyCachedClientsIfNeeded().
+    // TODO(wangxianzhu): In the future we can replace this with client-side repaint flags
+    // to avoid the cost of building and querying the hash table.
+    mutable HashSet<const DisplayItemClient*> m_validlyCachedClients;
+    mutable bool m_validlyCachedClientsDirty;
+
+    // Used during painting. Contains clients that have checked paint invalidation and
+    // are known to be valid.
+    // TODO(wangxianzhu): Use client side flag to avoid const of hash table.
+    HashSet<const DisplayItemClient*> m_clientsCheckedPaintInvalidation;
 
 #if ENABLE(ASSERT)
     // Set of clients which had paint offset changes since the last commit. This is used for
@@ -254,8 +275,6 @@
 #endif
 
     OwnPtr<Vector<String>> m_trackedPaintInvalidationObjects;
-
-    DisplayItemCacheGeneration m_currentCacheGeneration;
 };
 
 } // namespace blink