Adds support for headless chrome embedder mojo services

headless/lib/browser/headless_web_contents_impl.h

Index: headless/lib/browser/headless_web_contents_impl.h
diff --git a/headless/lib/browser/headless_web_contents_impl.h b/headless/lib/browser/headless_web_contents_impl.h
index e0eec04afa2f6e30115e2461c45b06620cdca072..d98ff372cb449ebbdf0a1389db27e236d3c98495 100644
--- a/headless/lib/browser/headless_web_contents_impl.h
+++ b/headless/lib/browser/headless_web_contents_impl.h
@@ -5,6 +5,7 @@
 #ifndef HEADLESS_LIB_BROWSER_HEADLESS_WEB_CONTENTS_IMPL_H_
 #define HEADLESS_LIB_BROWSER_HEADLESS_WEB_CONTENTS_IMPL_H_
 
+#include "content/public/browser/web_contents_observer.h"
 #include "headless/public/headless_devtools_target.h"
 #include "headless/public/headless_web_contents.h"
 
@@ -31,7 +32,8 @@ class HeadlessBrowserImpl;
 class WebContentsObserverAdapter;
 
 class HeadlessWebContentsImpl : public HeadlessWebContents,
-                                public HeadlessDevToolsTarget {
+                                public HeadlessDevToolsTarget,
+                                public content::WebContentsObserver {
  public:
   ~HeadlessWebContentsImpl() override;
 
@@ -54,6 +56,9 @@ class HeadlessWebContentsImpl : public HeadlessWebContents,
   void AttachClient(HeadlessDevToolsClient* client) override;
   void DetachClient(HeadlessDevToolsClient* client) override;
 
+  // content::WebContentsObserver implementation:
+  void RenderFrameCreated(content::RenderFrameHost* render_frame_host) override;
+
   content::WebContents* web_contents() const;
   bool OpenURL(const GURL& url);
 
@@ -67,10 +72,13 @@ class HeadlessWebContentsImpl : public HeadlessWebContents,
   void InitializeScreen(aura::Window* parent_window,
                         const gfx::Size& initial_size);
 
+  using MojoService = HeadlessWebContents::Builder::MojoService;
+
   class Delegate;
   std::unique_ptr<Delegate> web_contents_delegate_;
   std::unique_ptr<content::WebContents> web_contents_;
   scoped_refptr<content::DevToolsAgentHost> agent_host_;
+  std::list<MojoService> mojo_services_;
 
   HeadlessBrowserImpl* browser_;  // Not owned.