Fix bug where NVDA wouldn't enter browse mode on page load.

content/browser/accessibility/browser_accessibility_manager_win.cc

Index: content/browser/accessibility/browser_accessibility_manager_win.cc
diff --git a/content/browser/accessibility/browser_accessibility_manager_win.cc b/content/browser/accessibility/browser_accessibility_manager_win.cc
index 57989b6b15d3bba9b4eebfdc35a63063b4dbc910..984c9223268d2c549ab70460c7bc1e4b5f132d02 100644
--- a/content/browser/accessibility/browser_accessibility_manager_win.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_win.cc
@@ -134,6 +134,15 @@ void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
   if (node->GetRole() == ui::AX_ROLE_INLINE_TEXT_BOX)
     return;
 
+  // NVDA gets confused if we focus the main document element when it hasn't
+  // finished loading and it has no children at all, so suppress that event.
+  if (event_type == ui::AX_EVENT_FOCUS &&
+      node == GetRoot() &&
+      node->PlatformChildCount() == 0 &&
+      !node->GetBoolAttribute(ui::AX_ATTR_DOC_LOADED)) {
+    return;
+  }
+
   LONG event_id = EVENT_MIN;
   switch (event_type) {
     case ui::AX_EVENT_ACTIVEDESCENDANTCHANGED:
@@ -221,6 +230,10 @@ void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
     // object and pass it that same id, which we can use to retrieve the
     // IAccessible for this node.
     LONG child_id = node->ToBrowserAccessibilityWin()->unique_id_win();
+
+    // Always send a focus before a load complete.
+    if (event_type == ui::AX_EVENT_LOAD_COMPLETE)
+      MaybeCallNotifyWinEvent(EVENT_OBJECT_FOCUS, child_id);

[aboxhall, 2014/06/12 22:31:45]

Why is this necessary to fix this issue? Superficially it seems like this would
be the opposite of what you wanted, so I'm just curious.

[dmazzoni, 2014/06/12 23:27:22]

When we get a load complete, we know the document is fully loaded - it's
required to send a focus before sending a load complete. The fix up above says
to not send a focus if the document has only begun loading.

     MaybeCallNotifyWinEvent(event_id, child_id);
   }