Add native caching of uniquely keyed GrTextureProxies (take 2)

TBR=bsalomon@google.com

Change-Id: I590dcdc85fb60706c7eb06277694791dc04c9141
Reviewed-on: https://skia-review.googlesource.com/49543
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/gn/gpu.gni b/gn/gpu.gni
index 1a5687e..fbc976b 100644
--- a/gn/gpu.gni
+++ b/gn/gpu.gni
@@ -185,6 +185,7 @@
   "$_src/gpu/GrTessellator.h",
   "$_src/gpu/GrTextureOpList.cpp",
   "$_src/gpu/GrTextureOpList.h",
+  "$_src/gpu/GrTextureProxyCacheAccess.h",
   "$_src/gpu/GrTracing.h",
   "$_src/gpu/GrTestUtils.cpp",
   "$_src/gpu/GrTestUtils.h",