Implement a benchmark for GrResourceCache

gyp/bench.gyp

Index: gyp/bench.gyp
diff --git a/gyp/bench.gyp b/gyp/bench.gyp
index 040f7a4fcf217f145335ff4ac3ab2e9b8ea06897..4b32fe2400688f663dacd2e1c04c97605b293e9f 100644
--- a/gyp/bench.gyp
+++ b/gyp/bench.gyp
@@ -26,6 +26,7 @@
           {
             'include_dirs' : [
               '../src/gpu',
+              '../src/gpu/utils',
             ],
           },
         ],