Move memory histograms generation to MetricsMemoryDetails.

chrome/browser/memory_details_linux.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/memory_details.h"
 
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <map>
@@ skipping 50 matching lines @@
   { "firefox-bin", FIREFOX },
   { "iceweasel", ICEWEASEL },
   { "opera", OPERA },
   { "konqueror", KONQUEROR },
   { "epiphany-browse", EPIPHANY },
   { "epiphany", EPIPHANY },
   { "midori", MIDORI },
   { "", MAX_BROWSERS },
 };
 
-MemoryDetails::MemoryDetails()
-    : user_metrics_mode_(UPDATE_USER_METRICS),
-      memory_growth_tracker_(NULL) {
+MemoryDetails::MemoryDetails() {
 }
 
 ProcessData* MemoryDetails::ChromeBrowser() {
   return &process_data_[0];
 }
 
 struct Process {
   pid_t pid;
   pid_t parent;
   std::string name;
@@ skipping 152 matching lines @@
 
 #if defined(OS_CHROMEOS)
   base::GetSwapInfo(&swap_info_);
 #endif
 
   // Finally return to the browser thread.
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&MemoryDetails::CollectChildInfoOnUIThread, this));
 }