Removed call to DataReductionProxyStatisticsPrefs.

This removes a bug, which is in 2272 only, that attempts to write to
a DataReductionProxyStatisticsPrefs object after it has been
destroyed. The call is not needed.

BUG=459484
R=mmenke@chromium.org

Review URL: https://codereview.chromium.org/941483002

Cr-Commit-Position: refs/branch-heads/2272@{#329}
Cr-Branched-From: 827a380cfdb31aa54c8d56e63ce2c3fd8c3ba4d4-refs/heads/master@{#310958}

diff --git a/chrome/browser/profiles/profile_impl_io_data.cc b/chrome/browser/profiles/profile_impl_io_data.cc
index 80773eb..18d6e91 100644
--- a/chrome/browser/profiles/profile_impl_io_data.cc
+++ b/chrome/browser/profiles/profile_impl_io_data.cc

@@ -102,7 +102,6 @@
 
 ProfileImplIOData::Handle::~Handle() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  io_data_->data_reduction_proxy_statistics_prefs()->WritePrefs();
 
   if (io_data_->predictor_ != NULL) {
     // io_data_->predictor_ might be NULL if Init() was never called