Pipe the devTools FrameId from blink into the browser for headless

content/browser/devtools/devtools_agent_host_impl.cc

Index: content/browser/devtools/devtools_agent_host_impl.cc
diff --git a/content/browser/devtools/devtools_agent_host_impl.cc b/content/browser/devtools/devtools_agent_host_impl.cc
index a036c4c614c6b45e42d75fe5ab43feb7c1d980f3..92e9aa079110f3b036bd5f802a90dd2ce6f04956 100644
--- a/content/browser/devtools/devtools_agent_host_impl.cc
+++ b/content/browser/devtools/devtools_agent_host_impl.cc
@@ -21,7 +21,9 @@
 #include "content/browser/devtools/service_worker_devtools_manager.h"
 #include "content/browser/devtools/shared_worker_devtools_agent_host.h"
 #include "content/browser/devtools/shared_worker_devtools_manager.h"
+#include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/loader/netlog_observer.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 
@@ -58,6 +60,24 @@ bool DevToolsAgentHost::IsSupportedProtocolVersion(const std::string& version) {
 }
 
 // static
+std::string DevToolsAgentHost::GetUntrustedDevToolsFrameIdForFrameTreeNodeId(
+    int process_id,
+    int frame_tree_node_id) {
+  FrameTreeNode* frame_tree_node =
+      FrameTreeNode::GloballyFindByID(frame_tree_node_id);
+  if (!frame_tree_node)
+    return "";
+  // Make sure |process_id| hasn't changed.
+  RenderFrameHostImpl* render_frame_host_impl =
+      frame_tree_node->current_frame_host();
+  if (!render_frame_host_impl ||
+      render_frame_host_impl->GetProcess()->GetID() != process_id) {
+    return "";
+  }
+  return render_frame_host_impl->untrusted_devtools_frame_id();
+}
+
+// static
 DevToolsAgentHost::List DevToolsAgentHost::GetOrCreateAll() {
   List result;
   SharedWorkerDevToolsAgentHost::List shared_list;