[DevTools] Fix out of process iframes not working on chrome://inspect.

content/browser/devtools/render_frame_devtools_agent_host.cc

Index: content/browser/devtools/render_frame_devtools_agent_host.cc
diff --git a/content/browser/devtools/render_frame_devtools_agent_host.cc b/content/browser/devtools/render_frame_devtools_agent_host.cc
index d55be9332960e615fff19a921da7e285e6ffdad2..c2d13d65aa25319b23562ad25c325714aa6ad509 100644
--- a/content/browser/devtools/render_frame_devtools_agent_host.cc
+++ b/content/browser/devtools/render_frame_devtools_agent_host.cc
@@ -864,8 +864,8 @@ void RenderFrameDevToolsAgentHost::ConnectWebContents(WebContents* wc) {
 }
 
 std::string RenderFrameDevToolsAgentHost::GetParentId() {
-  if (IsChildFrame()) {
-    RenderFrameHostImpl* frame_host = current_->host();
+  if (IsChildFrame() && current_) {
+    RenderFrameHostImpl* frame_host = current_->host()->GetParent();
     while (frame_host && !ShouldCreateDevToolsFor(frame_host))
       frame_host = frame_host->GetParent();
     if (frame_host)