Implement initial support for nesting one ax tree in another.

content/browser/accessibility/browser_accessibility_manager.h

Index: content/browser/accessibility/browser_accessibility_manager.h
diff --git a/content/browser/accessibility/browser_accessibility_manager.h b/content/browser/accessibility/browser_accessibility_manager.h
index a5926c7b70f577fb93c07c76dbc7c17c5c151ce1..06c597bf2e1abf54a3dd4536f4734626f50100f7 100644
--- a/content/browser/accessibility/browser_accessibility_manager.h
+++ b/content/browser/accessibility/browser_accessibility_manager.h
@@ -69,7 +69,8 @@ class CONTENT_EXPORT BrowserAccessibilityFactory {
 };
 
 // Manages a tree of BrowserAccessibility objects.
-class CONTENT_EXPORT BrowserAccessibilityManager : public ui::AXTreeDelegate {
+class CONTENT_EXPORT BrowserAccessibilityManager
+    : public ui::AXTreeDelegate {

[David Tseng, 2014/05/01 18:07:54]

nit: why was this changed? I think it still fits on the previous line.

[dmazzoni, 2014/05/05 07:17:57]

Accident. Thanks.

  public:
   // Creates the platform-specific BrowserAccessibilityManager, but
   // with no parent window pointer. Only useful for unit tests.
@@ -178,6 +179,12 @@ class CONTENT_EXPORT BrowserAccessibilityManager : public ui::AXTreeDelegate {
   virtual void OnNodeChangeFinished(ui::AXNode* node) OVERRIDE;
   virtual void OnRootChanged(ui::AXNode* new_root) OVERRIDE {}
 
+  BrowserAccessibilityDelegate* delegate() const { return delegate_; }
+
+  // Frame tree support.
+  void SetParentFrameIds(int parent_frame_frame_id, int parent_frame_node_id);
+  BrowserAccessibility* GetCrossFrameParent();
+
  protected:
   BrowserAccessibilityManager(
       BrowserAccessibilityDelegate* delegate,
@@ -242,6 +249,12 @@ class CONTENT_EXPORT BrowserAccessibilityManager : public ui::AXTreeDelegate {
   // A mapping from a node id to its wrapper of type BrowserAccessibility.
   base::hash_map<int32, BrowserAccessibility*> id_wrapper_map_;
 
+  // The id of the parent frame and the hosting node within the parent frame.
+  // The parent frame id can be mapped to another BrowserAccessibilityManager
+  // using FrameTreeAccessibility.
+  int32 parent_frame_frame_id_;

[David Tseng, 2014/05/01 18:07:54]

I would split this comment into separate ones for each field since they are ids
for different set of objects.

[dmazzoni, 2014/05/05 07:17:57]

Done.

+  int32 parent_frame_node_id_;
+
   // The on-screen keyboard state.
   OnScreenKeyboardState osk_state_;