Prevent duplicate content script injection defined in manifest.json (reland)

extensions/renderer/scripts_run_info.h

Index: extensions/renderer/scripts_run_info.h
diff --git a/extensions/renderer/scripts_run_info.h b/extensions/renderer/scripts_run_info.h
index 6156eeb99be77ce74a67601e6cbaf8dda378e470..fb5531f07c74013c61986147f34e91ac72c80a5e 100644
--- a/extensions/renderer/scripts_run_info.h
+++ b/extensions/renderer/scripts_run_info.h
@@ -40,6 +40,8 @@ struct ScriptsRunInfo {
   ExecutingScriptsMap executing_scripts;
   // The elapsed time since the ScriptsRunInfo was constructed.
   base::ElapsedTimer timer;
+  // A list of extension urls of executing scripts.
+  std::set<GURL> injected_scripts;

[Devlin, 2016/09/06 17:21:13]

We don't need this anymore.  However, thinking about it, we probably *do* want
separate entries for injected js and injected css, since we notify the browser
about the injected js.  Let's add another ExecutingScriptsMap for
injected_stylesheets

[catmullings, 2016/09/07 01:00:35]

Done.

 
   // Log information about a given script run. If |send_script_activity| is
   // true, this also informs the browser of the script run.