rendering benchmark: Run canvas/webgl tests for longer.

Instead of running the webgl/canvas animations for 5 seconds, run
them a little longer: 10 seconds. The web-animation tests are also
currently run for 10 seconds. So this change aligns these animations.

There are ~35 canvas stories, and ~15 webgl stories. So overall, this
would increase the runtime, if all tests were to run on the same bot,
by ~4 minutes (= 50 * 5seconds). If the stories are sharded, then the
increased runtime should not be very noticeable.

BUG=894287

Change-Id: I62e341cfd3b605ab4090af2fc185fa1648324459
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1882760Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710605}

tools/perf/page_sets/rendering/tough_canvas_cases.py

@@ -29,7 +29,7 @@ class ToughCanvasPage(rendering_story.RenderingStory):
 
   def RunPageInteractions(self, action_runner):
     with action_runner.CreateInteraction('CanvasAnimation'):
-      action_runner.Wait(5)
+      action_runner.Wait(10)
 
 
 class MicrosoftFirefliesPage(ToughCanvasPage):

tools/perf/page_sets/rendering/tough_webgl_cases.py

@@ -38,7 +38,7 @@ class ToughWebglPage(rendering_story.RenderingStory):
 
   def RunPageInteractions(self, action_runner):
     with action_runner.CreateInteraction('WebGLAnimation'):
-      action_runner.Wait(5)
+      action_runner.Wait(10)
 
 
 class NvidiaVertexBufferObjectPage(ToughWebglPage):