Cleanup: Remove some unused code, or make them platform specific.

chrome/browser/chrome_net_benchmarking_message_filter.h

Index: chrome/browser/chrome_net_benchmarking_message_filter.h
===================================================================
--- chrome/browser/chrome_net_benchmarking_message_filter.h	(revision 246675)
+++ chrome/browser/chrome_net_benchmarking_message_filter.h	(working copy)
@@ -19,7 +19,6 @@
     : public content::BrowserMessageFilter {
  public:
   ChromeNetBenchmarkingMessageFilter(
-      int render_process_id,
       Profile* profile,
       net::URLRequestContextGetter* request_context);
 
@@ -41,8 +40,6 @@
   // Returns true if benchmarking is enabled for chrome.
   bool CheckBenchmarkingEnabled() const;
 
-  int render_process_id_;
-
   // The Profile associated with our renderer process.  This should only be
   // accessed on the UI thread!
   Profile* profile_;