Add Wait* API to ActionRunner to wrap over WaitAction.

tools/perf/page_sets/key_desktop_sites.py

Index: tools/perf/page_sets/key_desktop_sites.py
diff --git a/tools/perf/page_sets/key_desktop_sites.py b/tools/perf/page_sets/key_desktop_sites.py
index 9d7846369a0a74c65c0148f55611099344b9380c..6376aa3cf0c88445da35b16aa8895b4a02d892e1 100644
--- a/tools/perf/page_sets/key_desktop_sites.py
+++ b/tools/perf/page_sets/key_desktop_sites.py
@@ -45,11 +45,9 @@ class GmailPage(KeyDesktopSitesPage):
 
   def RunSmoothness(self, action_runner):
     action_runner.RunAction(ScrollAction())
-    action_runner.RunAction(WaitAction(
-      {
-        'javascript':
-        'window.gmonkey !== undefined && document.getElementById("gb") !== null'
-      }))
+    action_runner.WaitForJavaScriptCondition(
+        'window.gmonkey !== undefined && '
+        'document.getElementById("gb") !== null')
 
 
 class GoogleCalendarPage(KeyDesktopSitesPage):
@@ -81,11 +79,8 @@ class GoogleDrivePage(KeyDesktopSitesPage):
 
   def RunSmoothness(self, action_runner):
     action_runner.RunAction(ScrollAction())
-    action_runner.RunAction(WaitAction(
-      {
-        'javascript':
-        'document.getElementsByClassName("doclistview-list").length'
-      }))
+    action_runner.WaitForJavaScriptCondition(
+        'document.getElementsByClassName("doclistview-list").length')
 
 
 class GoogleDocPage(KeyDesktopSitesPage):
@@ -104,11 +99,8 @@ class GoogleDocPage(KeyDesktopSitesPage):
 
   def RunSmoothness(self, action_runner):
     action_runner.RunAction(ScrollAction())
-    action_runner.RunAction(WaitAction(
-      {
-        'javascript':
-        'document.getElementsByClassName("kix-appview-editor").length'
-      }))
+    action_runner.WaitForJavaScriptCondition(
+        'document.getElementsByClassName("kix-appview-editor").length')
 
 
 class KeyDesktopSitesPageSet(page_set_module.PageSet):