Reland CL to implement browser-side logging to WebRtc log.

content/public/browser/render_process_host.h

Index: content/public/browser/render_process_host.h
diff --git a/content/public/browser/render_process_host.h b/content/public/browser/render_process_host.h
index 436108a398bd7eef071a9c1001d6ea0d2d75804d..faa42ebe5e3b0949825289b3e1cd49221cdd4fd3 100644
--- a/content/public/browser/render_process_host.h
+++ b/content/public/browser/render_process_host.h
@@ -215,6 +215,12 @@ class CONTENT_EXPORT RenderProcessHost : public IPC::Sender,
 #if defined(ENABLE_WEBRTC)
   virtual void EnableAecDump(const base::FilePath& file) = 0;
   virtual void DisableAecDump() = 0;
+
+  // When set, |callback| receives log messages regarding, for example. media
+  // devices (webcams, mics, etc) that were initially requested in the render
+  // process associated with this RenderProcessHost.
+  virtual void SetWebRtcLogMessageCallback(
+      base::Callback<void(const std::string&)> callback) = 0;
 #endif
 
   // Static management functions -----------------------------------------------