Implement initial support for nesting one ax tree in another.

content/browser/accessibility/browser_accessibility_manager.cc

Index: content/browser/accessibility/browser_accessibility_manager.cc
diff --git a/content/browser/accessibility/browser_accessibility_manager.cc b/content/browser/accessibility/browser_accessibility_manager.cc
index fb6784113b3bd565e561b0f4abb97b225962675b..d85cfae2c7da595893ebee43403e46a191042a3f 100644
--- a/content/browser/accessibility/browser_accessibility_manager.cc
+++ b/content/browser/accessibility/browser_accessibility_manager.cc
@@ -6,6 +6,7 @@
 
 #include "base/logging.h"
 #include "content/browser/accessibility/browser_accessibility.h"
+#include "content/browser/accessibility/frame_tree_accessibility.h"
 #include "content/common/accessibility_messages.h"
 
 namespace content {
@@ -69,6 +70,8 @@ BrowserAccessibilityManager::BrowserAccessibilityManager(
       factory_(factory),
       tree_(new ui::AXTree()),
       focus_(NULL),
+      parent_frame_frame_id_(kNoFrameId),
+      parent_frame_node_id_(0),
       osk_state_(OSK_ALLOWED) {
   tree_->SetDelegate(this);
 }
@@ -344,4 +347,19 @@ void BrowserAccessibilityManager::OnNodeChangeFinished(ui::AXNode* node) {
   GetFromAXNode(node)->OnUpdateFinished();
 }
 
+void BrowserAccessibilityManager::SetParentFrameIds(
+    uint32 parent_frame_frame_id, uint32 parent_frame_node_id) {
+  parent_frame_frame_id_ = parent_frame_frame_id;
+  parent_frame_node_id_ = parent_frame_node_id;
+}
+
+BrowserAccessibility* BrowserAccessibilityManager::GetCrossFrameParent() {
+  FrameTreeAccessibility* frames = FrameTreeAccessibility::GetInstance();
+  BrowserAccessibilityManager* parent_manager =
+      frames->FindAccessibilityManagerById(parent_frame_frame_id_);
+  if (!parent_manager)
+    return NULL;
+  return parent_manager->GetFromID(parent_frame_node_id_);
+}
+
 }  // namespace content