Add deduping capability to SkPathHeap

src/core/SkPathHeap.h

Index: src/core/SkPathHeap.h
===================================================================
--- src/core/SkPathHeap.h	(revision 13690)
+++ src/core/SkPathHeap.h	(working copy)
@@ -30,6 +30,11 @@
      */
     int append(const SkPath&);
 
+    /** Add the specified path to the heap using its gen ID to de-duplicate.
+        Returns the path's index in the heap + 1.
+     */
+    int insert(const SkPath&);
+
     // called during picture-playback
     int count() const { return fPaths.count(); }
     const SkPath& operator[](int index) const {
@@ -44,6 +49,27 @@
     // we just store ptrs into fHeap here
     SkTDArray<SkPath*>  fPaths;
 
+    class LookupEntry {
+    public:
+        LookupEntry(const SkPath& path);
+
+        int storageSlot() const { return fStorageSlot; }
+        void setStorageSlot(int storageSlot) { fStorageSlot = storageSlot; }
+
+        static bool Less(const LookupEntry& a, const LookupEntry& b) {
+            return a.fGenerationID < b.fGenerationID;
+        }
+
+    private:
+        uint32_t fGenerationID;     // the SkPath's generation ID
+        // the path's index in the heap + 1. It is 0 if the path is not yet in the heap.
+        int      fStorageSlot;      
+    };
+
+    SkTDArray<LookupEntry> fLookupTable;
+
+    SkPathHeap::LookupEntry* addIfNotPresent(const SkPath& path);
+
     typedef SkRefCnt INHERITED;
 };