Pipe the devTools FrameId from blink into the browser for headless

headless/public/headless_web_contents.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HEADLESS_PUBLIC_HEADLESS_WEB_CONTENTS_H_
 #define HEADLESS_PUBLIC_HEADLESS_WEB_CONTENTS_H_
 
 #include <list>
 #include <string>
 #include <utility>
@@ skipping 59 matching lines @@
   virtual HeadlessDevToolsTarget* GetDevToolsTarget() = 0;
 
   // Close this page. |HeadlessWebContents| object will be destroyed.
   virtual void Close() = 0;
 
   // Returns the headless tab socket for JS -> C++ if one was created.
   virtual HeadlessTabSocket* GetHeadlessTabSocket() const = 0;
 
   // Returns the frame tree node id associated with the |devtools_agent_host_id|
   // if any.
+  // TODO(alexclarke): Remove this, it doesn't work as expected.
   virtual bool GetFrameTreeNodeIdForDevToolsAgentHostId(
       const std::string& devtools_agent_host_id,
       int* frame_tree_node_id) const = 0;
 
+  // Returns the devtools frame id corresponding to the |frame_tree_node_id|, if
+  // any.  Note this only works after we have received the data from blink.

[Sami, 2017/04/24 19:54:05]

nit: "after we have received the data from blink" is a little hard to interpret
at this level. Is there a notification we have to wait for?

[alex clarke (OOO till 29th), 2017/04/25 15:01:03]

Done.

+  virtual std::string GetDevToolsFrameIdForFrameTreeNodeId(

[Sami, 2017/04/24 19:54:05]

Could we put this (and the new method on HeadlessWebContents) just on the
corresponding impls instead of making them part of the public API? The reason is
that there isn't really a way to use this just through public headless API
(e.g., the render process ids or frame ids aren't exposed anywhere), and I
wouldn't want to encourage folks to start depending on random bits of content/
to get that data.

[alex clarke (OOO till 29th), 2017/04/25 15:01:03]

Done.

+      int frame_tree_node_id) const = 0;
+
  private:
   friend class HeadlessWebContentsImpl;
   HeadlessWebContents() {}
 
   DISALLOW_COPY_AND_ASSIGN(HeadlessWebContents);
 };
 
 class HEADLESS_EXPORT HeadlessWebContents::Builder {
  public:
   ~Builder();
@@ skipping 68 matching lines @@
   gfx::Size window_size_;
   std::list<MojoService> mojo_services_;
   bool create_tab_socket_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(Builder);
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_HEADLESS_WEB_CONTENTS_H_