Add GrMtlPipelineStateCache.

Allows us to cache MTLRenderPipelines rather than regenerating them
for every use.

Bug: skia:
Change-Id: I3357d3bc6d644074bd9d544a8d5205af56d918e5
Reviewed-on: https://skia-review.googlesource.com/c/195127
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
diff --git a/src/gpu/mtl/GrMtlGpuCommandBuffer.h b/src/gpu/mtl/GrMtlGpuCommandBuffer.h
index 1505789..322a2e8 100644
--- a/src/gpu/mtl/GrMtlGpuCommandBuffer.h
+++ b/src/gpu/mtl/GrMtlGpuCommandBuffer.h
@@ -73,8 +73,7 @@
             const GrPrimitiveProcessor& primProc,
             const GrPipeline& pipeline,
             const GrPipeline::FixedDynamicState* fixedDynamicState,
-            const GrMesh meshes[],
-            int meshCount);
+            GrPrimitiveType primType);
 
     void onDraw(const GrPrimitiveProcessor& primProc,
                 const GrPipeline& pipeline,