Add Wait* API to ActionRunner to wrap over WaitAction.

content/test/gpu/page_sets/gpu_rasterization_tests.py

Index: content/test/gpu/page_sets/gpu_rasterization_tests.py
diff --git a/content/test/gpu/page_sets/gpu_rasterization_tests.py b/content/test/gpu/page_sets/gpu_rasterization_tests.py
index e6a338f60969090dbc16f5e6277795a4e372e7b6..4933302c40c4a9a2f54b498ab6ab65a8e307dbae 100644
--- a/content/test/gpu/page_sets/gpu_rasterization_tests.py
+++ b/content/test/gpu/page_sets/gpu_rasterization_tests.py
@@ -69,11 +69,8 @@ class GpuRasterizationTestsPage(page_module.Page):
 
   def RunNavigateSteps(self, action_runner):
     action_runner.NavigateToPage(self)
-    action_runner.RunAction(WaitAction(
-      {
-        'javascript': 'domAutomationController._finished',
-        'timeout': 30
-      }))
+    action_runner.WaitForJavaScriptCondition(
+        'domAutomationController._finished', timeout=30)
 
 
 class GpuRasterizationTestsPageSet(page_set_module.PageSet):