SkRemoteGlyphCache  Add tracing to diff canvas

Use `extra_cflags=["-DSK_CAPTURE_DRAW_TEXT_BLOB"]` to enable.

Change-Id: I1d6db478ee91696cdce090647b889c17a83a2718
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/250259
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Herb Derby <herb@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index eddcf72..6c715d4 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1765,6 +1765,17 @@
     }
   }
 
+  if (!is_win) {
+    test_app("blob_cache_sim") {
+      sources = [
+        "tools/blob_cache_sim.cpp",
+      ]
+      deps = [
+        ":skia",
+      ]
+    }
+  }
+
   test_app("nanobench") {
     sources = [
       "bench/nanobench.cpp",