Collect some histograms about signed binary downloads.

chrome/browser/safe_browsing/safe_browsing_service.cc

 // Copyright (c) 2011 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/safe_browsing/safe_browsing_service.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/path_service.h"
@@ skipping 157 matching lines @@
       closing_database_(false),
       download_urlcheck_timeout_ms_(kDownloadUrlCheckTimeoutMs),
       download_hashcheck_timeout_ms_(kDownloadHashCheckTimeoutMs) {
 #if !defined(OS_CHROMEOS)
   if (!CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableClientSidePhishingDetection)) {
     csd_service_.reset(
         safe_browsing::ClientSideDetectionService::Create(
             g_browser_process->system_request_context()));
   }
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableImprovedDownloadProtection)) {
-    download_service_ = new safe_browsing::DownloadProtectionService(
-        this,
-        g_browser_process->system_request_context());
-  }
+  download_service_.reset(new safe_browsing::DownloadProtectionService(
+      this,
+      g_browser_process->system_request_context()));
 #endif
 }
 
 SafeBrowsingService::~SafeBrowsingService() {
+  ShutDownDownloadService();
+
   // Deletes the PrefChangeRegistrars, whose dtors also unregister |this| as an
   // observer of the preferences.
   STLDeleteValues(&prefs_map_);
 
   // We should have already been shut down. If we're still enabled, then the
   // database isn't going to be closed properly, which could lead to corruption.
   DCHECK(!enabled_);
 }
 
 void SafeBrowsingService::Initialize() {
@@ skipping 11 matching lines @@
   }
 
   // Track profile creation and destruction.
   prefs_registrar_.Add(this, chrome::NOTIFICATION_PROFILE_CREATED,
                        content::NotificationService::AllSources());
   prefs_registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
                        content::NotificationService::AllSources());
 }
 
 void SafeBrowsingService::ShutDown() {
-  if (download_service_.get()) {
-    // Disabling the download service first will ensure that it is
-    // disabled before the SafeBrowsingService object becomes invalid.  The
-    // download service might stay around for a bit since it's
-    // ref-counted but it won't do any harm because it will be
-    // disabled.
-    download_service_->SetEnabled(false);
-    download_service_ = NULL;
-  }
+  ShutDownDownloadService();
   Stop();
   // The IO thread is going away, so make sure the ClientSideDetectionService
   // dtor executes now since it may call the dtor of URLFetcher which relies
   // on it.
   csd_service_.reset();
 }
 
 bool SafeBrowsingService::CanCheckUrl(const GURL& url) const {
   return url.SchemeIs(chrome::kFtpScheme) ||
          url.SchemeIs(chrome::kHttpScheme) ||
@@ skipping 1123 matching lines @@
     }
   }
 
   if (enable)
     Start();
   else
     Stop();
 
   if (csd_service_.get())
     csd_service_->SetEnabledAndRefreshState(enable);
-  if (download_service_.get())
-    download_service_->SetEnabled(enable);
+  if (download_service_.get()) {
+    download_service_->SetEnabled(
+        enable && CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kEnableImprovedDownloadProtection));
+  }
 }
+
+void SafeBrowsingService::ShutDownDownloadService() {
+  if (download_service_.get()) {
+    BrowserThread::DeleteSoon(BrowserThread::IO, FROM_HERE,
+                              download_service_.release());
+  }
+}