Switch 4 more automation events to AXEventGenerator

These four events are (1) properly covered by AXEventGenerator,
(2) don't have any very specific logic in ChromeVox, they just
call onEventIfInRange, and (3) they aren't ever fired by views
in a place where AXEventGenerator wouldn't be able to infer the
same event.

For those reasons, these 4 are safe to switch over.

Bug: 699438
Change-Id: I05037a29e63e01b2be1a23c1057750ada24f0172
Reviewed-on: https://chromium-review.googlesource.com/1215058Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589977}

chrome/renderer/extensions/automation_ax_tree_wrapper.cc

@@ -320,6 +320,7 @@ bool AutomationAXTreeWrapper::IsEventTypeHandledByAXEventGenerator(
     case api::automation::EVENT_TYPE_ACTIVEDESCENDANTCHANGED:
     case api::automation::EVENT_TYPE_ARIAATTRIBUTECHANGED:
     case api::automation::EVENT_TYPE_CHECKEDSTATECHANGED:
+    case api::automation::EVENT_TYPE_CHILDRENCHANGED:
     case api::automation::EVENT_TYPE_DOCUMENTSELECTIONCHANGED:
     case api::automation::EVENT_TYPE_DOCUMENTTITLECHANGED:
     case api::automation::EVENT_TYPE_EXPANDEDCHANGED:
@@ -327,6 +328,9 @@ bool AutomationAXTreeWrapper::IsEventTypeHandledByAXEventGenerator(
     case api::automation::EVENT_TYPE_LIVEREGIONCHANGED:
     case api::automation::EVENT_TYPE_LIVEREGIONCREATED:
     case api::automation::EVENT_TYPE_LOADCOMPLETE:
+    case api::automation::EVENT_TYPE_ROWCOLLAPSED:
+    case api::automation::EVENT_TYPE_ROWCOUNTCHANGED:
+    case api::automation::EVENT_TYPE_ROWEXPANDED:
     case api::automation::EVENT_TYPE_SCROLLPOSITIONCHANGED:
     case api::automation::EVENT_TYPE_SELECTEDCHILDRENCHANGED:
       return true;
@@ -366,16 +370,12 @@ bool AutomationAXTreeWrapper::IsEventTypeHandledByAXEventGenerator(
     // These events might need to be migrated to AXEventGenerator.
     case api::automation::EVENT_TYPE_ALERT:
     case api::automation::EVENT_TYPE_BLUR:
-    case api::automation::EVENT_TYPE_CHILDRENCHANGED:
     case api::automation::EVENT_TYPE_FOCUS:
     case api::automation::EVENT_TYPE_IMAGEFRAMEUPDATED:
     case api::automation::EVENT_TYPE_LOCATIONCHANGED:
     case api::automation::EVENT_TYPE_MENUEND:
     case api::automation::EVENT_TYPE_MENULISTITEMSELECTED:
     case api::automation::EVENT_TYPE_MENUSTART:
-    case api::automation::EVENT_TYPE_ROWCOLLAPSED:
-    case api::automation::EVENT_TYPE_ROWCOUNTCHANGED:
-    case api::automation::EVENT_TYPE_ROWEXPANDED:
     case api::automation::EVENT_TYPE_SELECTION:
     case api::automation::EVENT_TYPE_TEXTCHANGED:
     case api::automation::EVENT_TYPE_TEXTSELECTIONCHANGED: