Parameterize the PrefService that AutofillDownloadManager uses.

components/autofill/core/browser/autofill_download.cc

Index: components/autofill/core/browser/autofill_download.cc
diff --git a/components/autofill/core/browser/autofill_download.cc b/components/autofill/core/browser/autofill_download.cc
index 9bf81e2c72bbcb71c64492e642ff9cee3f67eb06..994db7161eac34ae63ffd210af2208777b1080a0 100644
--- a/components/autofill/core/browser/autofill_download.cc
+++ b/components/autofill/core/browser/autofill_download.cc
@@ -18,7 +18,6 @@
 #include "components/autofill/core/browser/autofill_xml_parser.h"
 #include "components/autofill/core/browser/form_structure.h"
 #include "components/autofill/core/common/autofill_pref_names.h"
-#include "components/user_prefs/user_prefs.h"
 #include "content/public/browser/browser_context.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_response_headers.h"
@@ -70,8 +69,10 @@ struct AutofillDownloadManager::FormRequestData {
 };
 
 AutofillDownloadManager::AutofillDownloadManager(BrowserContext* context,
+                                                 PrefService* pref_service,
                                                  Observer* observer)
     : browser_context_(context),
+      pref_service_(pref_service),
       observer_(observer),
       max_form_cache_size_(kMaxFormCacheSize),
       next_query_request_(base::Time::Now()),
@@ -80,11 +81,10 @@ AutofillDownloadManager::AutofillDownloadManager(BrowserContext* context,
       negative_upload_rate_(0),
       fetcher_id_for_unittest_(0) {
   DCHECK(observer_);
-  PrefService* preferences = user_prefs::UserPrefs::Get(browser_context_);
   positive_upload_rate_ =
-      preferences->GetDouble(prefs::kAutofillPositiveUploadRate);
+      pref_service_->GetDouble(prefs::kAutofillPositiveUploadRate);
   negative_upload_rate_ =
-      preferences->GetDouble(prefs::kAutofillNegativeUploadRate);
+      pref_service_->GetDouble(prefs::kAutofillNegativeUploadRate);
 }
 
 AutofillDownloadManager::~AutofillDownloadManager() {
@@ -170,8 +170,7 @@ void AutofillDownloadManager::SetPositiveUploadRate(double rate) {
   positive_upload_rate_ = rate;
   DCHECK_GE(rate, 0.0);
   DCHECK_LE(rate, 1.0);
-  PrefService* preferences = user_prefs::UserPrefs::Get(browser_context_);
-  preferences->SetDouble(prefs::kAutofillPositiveUploadRate, rate);
+  pref_service_->SetDouble(prefs::kAutofillPositiveUploadRate, rate);
 }
 
 void AutofillDownloadManager::SetNegativeUploadRate(double rate) {
@@ -180,8 +179,7 @@ void AutofillDownloadManager::SetNegativeUploadRate(double rate) {
   negative_upload_rate_ = rate;
   DCHECK_GE(rate, 0.0);
   DCHECK_LE(rate, 1.0);
-  PrefService* preferences = user_prefs::UserPrefs::Get(browser_context_);
-  preferences->SetDouble(prefs::kAutofillNegativeUploadRate, rate);
+  pref_service_->SetDouble(prefs::kAutofillNegativeUploadRate, rate);
 }
 
 bool AutofillDownloadManager::StartRequest(