Refactor GrBufferAllocPools to use resource cache

src/gpu/GrVertexBuffer.h

Index: src/gpu/GrVertexBuffer.h
diff --git a/src/gpu/GrVertexBuffer.h b/src/gpu/GrVertexBuffer.h
index 3f2ada2a2c50eb15f3a372b147e2df162c95caa9..3c12cd76d2a6b496ec9e40410ded571534571207 100644
--- a/src/gpu/GrVertexBuffer.h
+++ b/src/gpu/GrVertexBuffer.h
@@ -14,9 +14,24 @@
 #include "GrGeometryBuffer.h"
 
 class GrVertexBuffer : public GrGeometryBuffer {
+public:
+    static void ComputeScratchKey(size_t size, bool dynamic, GrScratchKey* key) {
+        static const GrScratchKey::ResourceType kType = GrScratchKey::GenerateResourceType();
+
+        GrScratchKey::Builder builder(key, kType, 2);
+
+        builder[0] = SkToUInt(size);
+        builder[1] = dynamic ? 1 : 0;
+    }
+
 protected:
     GrVertexBuffer(GrGpu* gpu, size_t gpuMemorySize, bool dynamic, bool cpuBacked)
-        : INHERITED(gpu, gpuMemorySize, dynamic, cpuBacked) {}
+        : INHERITED(gpu, gpuMemorySize, dynamic, cpuBacked) {
+        GrScratchKey key;
+        ComputeScratchKey(gpuMemorySize, dynamic, &key);
+        this->setScratchKey(key);
+    }
+
 private:
     typedef GrGeometryBuffer INHERITED;
 };