Updated AccessibilityNotificationWaiter to also wait for focus events

AccessibilityNotificationWaiter is part of the accessibility browser tests infrastructure.
Focus events are fired via a different mechanism in BrowserAccessibilityManager than all other Blink-based or generated events.
In order to write effective tests that check if a focus event has been fired,
we need to modify AccessibilityNotificationWaiter to watch for focus events too.
R=aboxhall@chromium.org

Change-Id: I1e8730442cd733f51b7510592e0f9f0bc6f3c2a3
Bug: 982776
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1692104
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Alice Boxhall <aboxhall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676140}

content/browser/accessibility/browser_accessibility_manager_android.cc

@@ -213,6 +213,7 @@ void BrowserAccessibilityManagerAndroid::FireGeneratedEvent(
     case ui::AXEventGenerator::Event::DROPEFFECT_CHANGED:
     case ui::AXEventGenerator::Event::EXPANDED:
     case ui::AXEventGenerator::Event::ENABLED_CHANGED:
+    case ui::AXEventGenerator::Event::FOCUS_CHANGED:
     case ui::AXEventGenerator::Event::FLOW_FROM_CHANGED:
     case ui::AXEventGenerator::Event::FLOW_TO_CHANGED:
     case ui::AXEventGenerator::Event::GRABBED_CHANGED:

content/browser/accessibility/browser_accessibility_manager_mac.mm

@@ -383,6 +383,7 @@ void BrowserAccessibilityManagerMac::FireGeneratedEvent(
     case ui::AXEventGenerator::Event::DOCUMENT_TITLE_CHANGED:
     case ui::AXEventGenerator::Event::DROPEFFECT_CHANGED:
     case ui::AXEventGenerator::Event::ENABLED_CHANGED:
+    case ui::AXEventGenerator::Event::FOCUS_CHANGED:
     case ui::AXEventGenerator::Event::FLOW_FROM_CHANGED:
     case ui::AXEventGenerator::Event::FLOW_TO_CHANGED:
     case ui::AXEventGenerator::Event::GRABBED_CHANGED:

content/browser/accessibility/browser_accessibility_manager_win.cc

@@ -396,6 +396,7 @@ void BrowserAccessibilityManagerWin::FireGeneratedEvent(
       break;
     case ui::AXEventGenerator::Event::AUTO_COMPLETE_CHANGED:
     case ui::AXEventGenerator::Event::DOCUMENT_TITLE_CHANGED:
+    case ui::AXEventGenerator::Event::FOCUS_CHANGED:
     case ui::AXEventGenerator::Event::LIVE_REGION_NODE_CHANGED:
     case ui::AXEventGenerator::Event::LOAD_START:
     case ui::AXEventGenerator::Event::MENU_ITEM_SELECTED:

content/test/accessibility_browser_test_utils.cc

@@ -10,6 +10,7 @@
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "content/browser/accessibility/browser_accessibility.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
@@ -151,6 +152,9 @@ void AccessibilityNotificationWaiter::BindOnGeneratedEvent(
     manager->SetGeneratedEventCallbackForTesting(
         base::BindRepeating(&AccessibilityNotificationWaiter::OnGeneratedEvent,
                             weak_factory_.GetWeakPtr()));
+    manager->SetFocusChangeCallbackForTesting(
+        base::BindRepeating(&AccessibilityNotificationWaiter::OnFocusChanged,
+                            weak_factory_.GetWeakPtr()));
   }
 }
 
@@ -168,6 +172,20 @@ void AccessibilityNotificationWaiter::OnGeneratedEvent(
   }
 }
 
+// TODO(982776): Remove this method once we migrate to using AXEventGenerator
+// for focus changed events.
+void AccessibilityNotificationWaiter::OnFocusChanged() {
+  WebContentsImpl* web_contents_impl =
+      static_cast<WebContentsImpl*>(web_contents());
+  const BrowserAccessibilityManager* manager =
+      web_contents_impl->GetRootBrowserAccessibilityManager();
+  if (manager && manager->delegate() && manager->GetFocus()) {
+    OnGeneratedEvent(manager->delegate(),
+                     ui::AXEventGenerator::Event::FOCUS_CHANGED,
+                     manager->GetFocus()->GetId());
+  }
+}
+
 bool AccessibilityNotificationWaiter::IsAboutBlank() {
   // Skip any accessibility notifications related to "about:blank",
   // to avoid a possible race condition between the test beginning

content/test/accessibility_browser_test_utils.h

@@ -82,19 +82,25 @@ class AccessibilityNotificationWaiter : public WebContentsObserver {
   // Helper to bind the OnAccessibilityEvent callback
   void BindOnAccessibilityEvent(RenderFrameHostImpl* frame_host);
 
+  // Helper to bind the OnGeneratedEvent callback
+  void BindOnGeneratedEvent(RenderFrameHostImpl* frame_host);
+
   // Callback from RenderViewHostImpl.
   void OnAccessibilityEvent(RenderFrameHostImpl* rfhi,
                             ax::mojom::Event event,
                             int event_target_id);
 
-  // Helper to bind the OnGeneratedEvent callback
-  void BindOnGeneratedEvent(RenderFrameHostImpl* frame_host);
-
-  // Callback from BrowserAccessibilityManager
+  // Callback from BrowserAccessibilityManager for all generated events.
   void OnGeneratedEvent(BrowserAccessibilityDelegate* delegate,
                         ui::AXEventGenerator::Event event,
                         int event_target_id);
 
+  // Callback from BrowserAccessibilityManager for the focus changed event.
+  //
+  // TODO(982776): Remove this method once we migrate to using AXEventGenerator
+  // for focus changed events.
+  void OnFocusChanged();
+
   // Helper function to determine if the accessibility tree in
   // GetAXTree() is about the page with the url "about:blank".
   bool IsAboutBlank();

extensions/renderer/api/automation/automation_ax_tree_wrapper.cc

@@ -198,6 +198,7 @@ api::automation::EventType ToAutomationEvent(
     case ui::AXEventGenerator::Event::DESCRIPTION_CHANGED:
     case ui::AXEventGenerator::Event::DROPEFFECT_CHANGED:
     case ui::AXEventGenerator::Event::ENABLED_CHANGED:
+    case ui::AXEventGenerator::Event::FOCUS_CHANGED:
     case ui::AXEventGenerator::Event::FLOW_FROM_CHANGED:
     case ui::AXEventGenerator::Event::FLOW_TO_CHANGED:
     case ui::AXEventGenerator::Event::GRABBED_CHANGED:

ui/accessibility/ax_event_generator.h

@@ -40,6 +40,7 @@ class AX_EXPORT AXEventGenerator : public AXTreeObserver {
     DROPEFFECT_CHANGED,
     ENABLED_CHANGED,
     EXPANDED,
+    FOCUS_CHANGED,
     FLOW_FROM_CHANGED,
     FLOW_TO_CHANGED,
     GRABBED_CHANGED,