Change VkPipelineStateCahce to use Hash and LRU LList.

src/gpu/vk/GrVkGpu.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrVkGpu_DEFINED
 #define GrVkGpu_DEFINED
 
@@ skipping 142 matching lines @@
                        int left, int top, int width, int height,
                        GrPixelConfig config, const SkTArray<GrMipLevel>&) override;
 
     bool onTransferPixels(GrSurface*,
                           int left, int top, int width, int height,
                           GrPixelConfig config, GrBuffer* transferBuffer,
                           size_t offset, size_t rowBytes) override { return false; }
 
     void onResolveRenderTarget(GrRenderTarget* target) override {}
 
-    bool prepareDrawState(const GrPipeline&,
-                          const GrPrimitiveProcessor&,
-                          GrPrimitiveType,
-                          const GrVkRenderPass&,
-                          GrVkPipelineState** pipelineState);
+    sk_sp<GrVkPipelineState> prepareDrawState(const GrPipeline&,
+                                              const GrPrimitiveProcessor&,
+                                              GrPrimitiveType,
+                                              const GrVkRenderPass&);
 
     // Bind vertex and index buffers
     void bindGeometry(const GrPrimitiveProcessor&, const GrNonInstancedMesh&);
 
     // Ends and submits the current command buffer to the queue and then creates a new command
     // buffer and begins it. If sync is set to kForce_SyncQueue, the function will wait for all 
     // work in the queue to finish before returning.
     void submitCommandBuffer(SyncQueue sync);
 
     void copySurfaceAsCopyImage(GrSurface* dst,
@@ skipping 35 matching lines @@
 
     // Shaderc compiler used for compiling glsl in spirv. We only want to create the compiler once
     // since there is significant overhead to the first compile of any compiler.
     shaderc_compiler_t fCompiler;
 
 
     typedef GrGpu INHERITED;
 };
 
 #endif