Do not fire events on trimmed descendants of leaf nodes

NOTRY:true

Bug: 887512
Change-Id: Ie4aab44d8eb186b9aff35036aa5317c6f79fc643
Reviewed-on: https://chromium-review.googlesource.com/1236714
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593562}

content/browser/accessibility/browser_accessibility_manager.cc

@@ -373,7 +373,7 @@ void BrowserAccessibilityManager::OnAccessibilityEvents(
   // Fire any events related to changes to the tree.
   for (auto targeted_event : *this) {
     BrowserAccessibility* event_target = GetFromAXNode(targeted_event.node);
-    if (!event_target)
+    if (!event_target || event_target->PlatformIsChildOfLeaf())
       continue;
 
     FireGeneratedEvent(targeted_event.event_params.event, event_target);
@@ -386,7 +386,7 @@ void BrowserAccessibilityManager::OnAccessibilityEvents(
 
     // Fire the native event.
     BrowserAccessibility* event_target = GetFromID(event.id);
-    if (!event_target)
+    if (!event_target || event_target->PlatformIsChildOfLeaf())
       return;
 
     if (event.event_type == ax::mojom::Event::kHover)

content/browser/accessibility/browser_accessibility_manager_win.cc

@@ -197,6 +197,9 @@ void BrowserAccessibilityManagerWin::FireGeneratedEvent(
 void BrowserAccessibilityManagerWin::FireWinAccessibilityEvent(
     LONG win_event_type,
     BrowserAccessibility* node) {
+  if (node->PlatformIsChildOfLeaf())
+    return;
+
   // If there's no root delegate, this may be a new frame that hasn't
   // yet been swapped in or added to the frame tree. Suppress firing events
   // until then.

content/test/data/accessibility/event/caret-move-expected-win.txt

@@ -6,4 +6,3 @@ EVENT_OBJECT_SHOW role=ROLE_SYSTEM_CARET  window_class=Chrome_WidgetWin_0
 EVENT_OBJECT_VALUECHANGE on <input#in1> role=ROLE_SYSTEM_TEXT value="end" FOCUSABLE IA2_STATE_EDITABLE,IA2_STATE_SELECTABLE_TEXT,IA2_STATE_SINGLE_LINE
 IA2_EVENT_TEXT_CARET_MOVED on <input#in1> role=ROLE_SYSTEM_TEXT value="abcde" FOCUSED,FOCUSABLE IA2_STATE_EDITABLE,IA2_STATE_SELECTABLE_TEXT,IA2_STATE_SINGLE_LINE
 IA2_EVENT_TEXT_CARET_MOVED on <input#in1> role=ROLE_SYSTEM_TEXT value="abcde" FOCUSED,FOCUSABLE IA2_STATE_EDITABLE,IA2_STATE_SELECTABLE_TEXT,IA2_STATE_SINGLE_LINE
-IA2_EVENT_TEXT_CARET_MOVED on role=ROLE_SYSTEM_STATICTEXT name="abcde" IA2_STATE_EDITABLE
\ No newline at end of file