Add GrProxyProvider

This pulls all the proxy tracking & creation functionality out of the GrResourceCache and GrResourceProvider and consolidates it in the GrProxyProvider.

Change-Id: I7256f7c544319a70c1bd93dd5a9ccbe5fa0a544f
Reviewed-on: https://skia-review.googlesource.com/91501
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/gn/gpu.gni b/gn/gpu.gni
index f41dc4a..a9e3ade 100644
--- a/gn/gpu.gni
+++ b/gn/gpu.gni
@@ -142,6 +142,8 @@
   "$_src/gpu/GrProcessorAnalysis.h",
   "$_src/gpu/GrProcessorUnitTest.cpp",
   "$_src/gpu/GrProcessorUnitTest.h",
+  "$_src/gpu/GrProxyProvider.cpp",
+  "$_src/gpu/GrProxyProvider.h",
   "$_src/gpu/GrGpuResourceRef.cpp",
   "$_src/gpu/GrQuad.h",
   "$_src/gpu/GrRect.h",