Switch the TCP reads on Windows to use non-blocking/non-async I/O.

chrome/browser/chrome_browser_field_trials.h

Index: chrome/browser/chrome_browser_field_trials.h
===================================================================
--- chrome/browser/chrome_browser_field_trials.h	(revision 163292)
+++ chrome/browser/chrome_browser_field_trials.h	(working copy)
@@ -71,6 +71,10 @@
   // Sets up field trials for doing Cache Sensitivity Analysis.
   void SetUpCacheSensitivityAnalysisFieldTrial();
 
+  // A field trial to determine the impact of using non-blocking reads for
+  // TCP sockets on Windows instead of overlapped I/O.
+  void WindowsOverlappedTCPReadsFieldTrial();
+
   const CommandLine& parsed_command_line_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserFieldTrials);