Add text size animation to silk page set

tools/perf/page_sets/key_silk_cases.py

Index: tools/perf/page_sets/key_silk_cases.py
diff --git a/tools/perf/page_sets/key_silk_cases.py b/tools/perf/page_sets/key_silk_cases.py
index ca5a817e2a728635e41f41e11ebdae4152e0f221..badfd4fc91c133f4faa957a2bf463ce8c67a175a 100644
--- a/tools/perf/page_sets/key_silk_cases.py
+++ b/tools/perf/page_sets/key_silk_cases.py
@@ -633,6 +633,21 @@ class UpdateHistoryState(KeySilkCasesPage):
     interaction.End()
 
 
+class TextSizeAnimation(KeySilkCasesPage):
+
+  """ Why: Scale animation with text. """
+
+  def __init__(self, page_set):
+    super(TextSizeAnimation, self).__init__(
+      url='http://jsbin.com/gikex/2/quiet',
+      page_set=page_set)
+
+    self.gpu_raster = True
+
+  def RunSmoothness(self, action_runner):
+    action_runner.Wait(4)
+
+
 class KeySilkCasesPageSet(page_set_module.PageSet):
 
   """ Pages hand-picked for project Silk. """
@@ -674,3 +689,4 @@ class KeySilkCasesPageSet(page_set_module.PageSet):
     self.AddPage(Page26(self))
     self.AddPage(SVGIconRaster(self))
     self.AddPage(UpdateHistoryState(self))
+    self.AddPage(TextSizeAnimation(self))