Add GN target for skpinfo

BUG=skia:6178

Change-Id: If6f96063fcb4e541da560ff00b925fd8098ce6b9
Reviewed-on: https://skia-review.googlesource.com/7791
Commit-Queue: Ravi Mistry <rmistry@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 390f136..25b68b4 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1147,6 +1147,16 @@
     ]
   }
 
+  test_app("skpinfo") {
+    sources = [
+      "tools/skpinfo.cpp",
+    ]
+    deps = [
+      ":flags",
+      ":skia",
+    ]
+  }
+
   if (is_linux || is_win || is_mac) {
     test_app("SampleApp") {
       sources = [