Implement vertex buffer caching in the tessellated path renderer.

include/gpu/GrResourceKey.h

Index: include/gpu/GrResourceKey.h
diff --git a/include/gpu/GrResourceKey.h b/include/gpu/GrResourceKey.h
index a353dc21143766f0a1cb7a2a598e9c55dc2c375b..0a97c20b4d5420bc9d819d3d27142bccf1c743b1 100644
--- a/include/gpu/GrResourceKey.h
+++ b/include/gpu/GrResourceKey.h
@@ -10,6 +10,7 @@
 #define GrResourceKey_DEFINED
 
 #include "GrTypes.h"
+#include "SkData.h"
 #include "SkOnce.h"
 #include "SkTemplates.h"
 
@@ -237,6 +238,7 @@ public:
 
     GrUniqueKey& operator=(const GrUniqueKey& that) {
         this->INHERITED::operator=(that);
+        this->setCustomData(that.getCustomData());
         return *this;
     }
 
@@ -245,6 +247,14 @@ public:
     }
     bool operator!=(const GrUniqueKey& that) const { return !(*this == that); }
 
+    void setCustomData(const SkData* data) {
+        SkSafeRef(data);
+        fData.reset(data);
+    }
+    const SkData* getCustomData() const {
+        return fData.get();
+    }
+
     class Builder : public INHERITED::Builder {
     public:
         Builder(GrUniqueKey* key, Domain domain, int data32Count)
@@ -268,6 +278,9 @@ public:
             return SkToInt((innerKey.dataSize() >> 2) + 1);
         }
     };
+
+private:
+    SkAutoTUnref<const SkData> fData;
 };
 
 /**