Use FrameTreeNode ID as frameId in extension APIs

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 84c579d8a494dc03e44a932f6250579806aacbf8..1609a1b1c59b55b990df124db75f03fccdbb9403 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -118,6 +118,7 @@ class CONTENT_EXPORT RenderFrameHostImpl
   static const int kMaxAccessibilityResets = 5;
 
   static RenderFrameHostImpl* FromID(int process_id, int routing_id);
+  static RenderFrameHostImpl* FromFrameTreeNodeID(int frame_tree_node_id);
   static RenderFrameHostImpl* FromAXTreeID(
       AXTreeIDRegistry::AXTreeID ax_tree_id);
 
@@ -129,6 +130,8 @@ class CONTENT_EXPORT RenderFrameHostImpl
   SiteInstanceImpl* GetSiteInstance() override;
   RenderProcessHost* GetProcess() override;
   RenderFrameHost* GetParent() override;
+  RenderFrameHost* FindByFrameTreeNodeID(int frame_tree_node_id) override;
+  int GetFrameTreeNodeID() override;
   const std::string& GetFrameName() override;
   bool IsCrossProcessSubframe() override;
   GURL GetLastCommittedURL() override;