Pass RapporService to content/browser/

content/browser/renderer_host/render_widget_host_delegate.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_DELEGATE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_DELEGATE_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 218 matching lines @@
   // focused WebContents.
   virtual RenderWidgetHostImpl* GetRenderWidgetHostWithPageFocus();
 
   // In cases with multiple RenderWidgetHosts involved in rendering a page, only
   // one widget should be focused and active. This ensures that
   // |render_widget_host| is focused and that its owning WebContents is also
   // the focused WebContents.
   virtual void FocusOwningWebContents(
       RenderWidgetHostImpl* render_widget_host) {}
 
+  // Returns the eTLD+1 of the current page.
+  virtual std::string GetRapporCommittedUrl();

[ncarter (slow), 2016/12/01 22:33:32]

As we were discussing before, this looks out of place here here because the URL
is not widget state -- widgets don't navigate or load things from the network.

However, I had a look at your motivating CL, and understand now the problem that
this solves. What's happening is that we have gathered some stats way down in a
stats-tracking helper, and we need to percolate up to the delegate to add the
eTLD+1 context.

What if we structured the method like this:

// Augment a Rappor sample with eTLD+1 context. The caller is still responsible
// for logging the sample to the RapporService. Returns false if the eTLD+1
// is not known for |render_widget_host|.
virtual bool AddDomainInfoToRapporSample(
    RenderWidgetHostImpl* render_widget_host,
    rappor::Sample* sample);

Does that work?

[Navid Zolghadr, 2016/12/02 20:47:35]

Sure. Sounds good. But why do I need RenderWidgetHostImpl*?

[ncarter (slow), 2016/12/05 19:50:50]

There can be arbitrarily many RenderWidgetHosts inside a WebContents, all
sharing a delegate, so I default to expecting that methods on the delegate will
pass the pointer. However, it's okay to plumb this as needed.

+
  protected:
   virtual ~RenderWidgetHostDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_DELEGATE_H_