Add robohornet as an animation test

tools/perf/page_sets/tough_texture_upload_cases.json

Index: tools/perf/page_sets/tough_texture_upload_cases.json
diff --git a/tools/perf/page_sets/tough_texture_upload_cases.json b/tools/perf/page_sets/tough_texture_upload_cases.json
index d60aded34d52da2a7cc3fce0f3491d993faca935..e96f7b2a38bd5db653089f85d200d44cfde270ab 100644
--- a/tools/perf/page_sets/tough_texture_upload_cases.json
+++ b/tools/perf/page_sets/tough_texture_upload_cases.json
@@ -3,25 +3,25 @@
   "pages": [
     {
       "url": "file:///tough_texture_upload_cases/background_color_animation.html",
-      "scrolling": {
+      "smoothness": {
           "action": "scrolling_interaction"
       }
     },
     {
       "url": "file:///tough_texture_upload_cases/background_color_animation_and_transform_animation.html",
-      "scrolling": {
+      "smoothness": {
           "action": "scrolling_interaction"
       }
     },
     {
       "url": "file:///tough_texture_upload_cases/background_color_animation_with_gradient.html",
-      "scrolling": {
+      "smoothness": {
           "action": "scrolling_interaction"
       }
     },
     {
       "url": "file:///tough_texture_upload_cases/background_color_animation_with_gradient_and_transform_animation.html",
-      "scrolling": {
+      "smoothness": {
           "action": "scrolling_interaction"
       }
     }