Reset accessibility if it gets out of sync.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 60cdea90b957f5f6f43b6d811c3a566ae647004f..8be166c21f98db4f3e6b21223b9666facb99d912 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -293,6 +293,10 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // NULL.
   BrowserAccessibilityManager* GetOrCreateBrowserAccessibilityManager();
 
+  void set_disallow_browser_accessibility_manager_for_testing(bool flag) {
+    disallow_browser_accessibility_manager_for_testing_ = flag;
+  }
+
 #if defined(OS_WIN)
   void SetParentNativeViewAccessible(
       gfx::NativeViewAccessible accessible_parent);
@@ -378,7 +382,8 @@ class CONTENT_EXPORT RenderFrameHostImpl
   void OnBeginNavigation(
       const FrameHostMsg_BeginNavigation_Params& params);
   void OnAccessibilityEvents(
-      const std::vector<AccessibilityHostMsg_EventParams>& params);
+      const std::vector<AccessibilityHostMsg_EventParams>& params,
+      bool is_reset);
   void OnAccessibilityLocationChanges(
       const std::vector<AccessibilityHostMsg_LocationChangeParams>& params);
 
@@ -476,12 +481,23 @@ class CONTENT_EXPORT RenderFrameHostImpl
 
   ServiceRegistryImpl service_registry_;
 
+  // The object managing the accessibility tree for this frame.
   scoped_ptr<BrowserAccessibilityManager> browser_accessibility_manager_;
 
+  // True if we sent an accessibility reset to the renderer and we're
+  // waiting for a complete tree in response.
+  bool waiting_on_accessibility_reset_;

[nasko, 2014/10/02 16:38:48]

It will be nice to think about whether all accessibility code can be moved to a
separate object that RFH owns. One of my worries is RFH becoming a monster of an
object in the long run. Nothing to do for this CL, but some thinking to do as we
complete the out-of-process iframes transition for accessibility.

[dmazzoni, 2014/10/02 21:51:12]

Sure, I've been thinking about this too. If you think it'd be okay for it to be
a sibling class (i.e. dependencies can go both directions) then it'd be super
easy.

+
+  // A count of the number of times we needed to reset accessibility, so
+  // we don't keep trying to reset forever.
+  int accessibility_reset_count_;
+
   // Callback when an event is received, for testing.
   base::Callback<void(ui::AXEvent, int)> accessibility_testing_callback_;
   // The most recently received accessibility tree - for testing only.
   scoped_ptr<ui::AXTree> ax_tree_for_testing_;
+  // Flag to not create a BrowserAccessibilityManager, for testing.
+  bool disallow_browser_accessibility_manager_for_testing_;
 
   // NOTE: This must be the last member.
   base::WeakPtrFactory<RenderFrameHostImpl> weak_ptr_factory_;