Override CreateNewTarget in the HeadlessDevToolsManagerDelegate to be able to create new tabs in he…

headless/lib/browser/headless_devtools_manager_delegate.cc

Index: headless/lib/browser/headless_devtools_manager_delegate.cc
diff --git a/headless/lib/browser/headless_devtools_manager_delegate.cc b/headless/lib/browser/headless_devtools_manager_delegate.cc
index 0842569beb351818acfff0eb7dc584caf30f129d..3ecf23d9a473e4f2f30696383b7d91ba89ee068b 100644
--- a/headless/lib/browser/headless_devtools_manager_delegate.cc
+++ b/headless/lib/browser/headless_devtools_manager_delegate.cc
@@ -108,6 +108,18 @@ base::DictionaryValue* HeadlessDevToolsManagerDelegate::HandleCommand(
   return cmd_result.release();
 }
 
+scoped_refptr<content::DevToolsAgentHost>
+HeadlessDevToolsManagerDelegate::CreateNewTarget(const GURL& url) {
+  HeadlessBrowserContext* context = browser_->GetDefaultBrowserContext();
+  HeadlessWebContentsImpl* web_contents_impl = HeadlessWebContentsImpl::From(
+      context->CreateWebContentsBuilder()
+          .SetInitialURL(url)
+          .SetWindowSize(browser_->options()->window_size)
+          .Build());
+  return content::DevToolsAgentHost::GetOrCreateFor(
+      web_contents_impl->web_contents());
+}
+
 std::string HeadlessDevToolsManagerDelegate::GetDiscoveryPageHTML() {
   return ResourceBundle::GetSharedInstance()
       .GetRawDataResource(IDR_HEADLESS_LIB_DEVTOOLS_DISCOVERY_PAGE)