Remove call to RegisterUserPrefsOnBrowserContextForTest

The preferences are already correctly registered as part of the
creation of the TestingProfile so there is no need to call this
method (it is deprecated).

Bug: 932534
Change-Id: I1898d7a55e21f2a6524df3d84d849fa428f9c944
Reviewed-on: https://chromium-review.googlesource.com/c/1474760
Commit-Queue: Drew Wilson <atwilson@chromium.org>
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Drew Wilson <atwilson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632709}

chrome/browser/background/background_contents_service_unittest.cc

@@ -168,8 +168,7 @@ TEST_F(BackgroundContentsServiceTest, BackgroundContentsCreateDestroy) {
 TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAdded) {
   TestingProfile profile;
   BackgroundContentsService service(&profile, command_line_.get());
-  BackgroundContentsServiceFactory::GetInstance()
-      ->RegisterUserPrefsOnBrowserContextForTest(&profile);
+
   GURL orig_url;
   GURL url("http://a/");
   GURL url2("http://a/");
@@ -195,8 +194,6 @@ TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAdded) {
 TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAddedAndClosed) {
   TestingProfile profile;
   BackgroundContentsService service(&profile, command_line_.get());
-  BackgroundContentsServiceFactory::GetInstance()
-      ->RegisterUserPrefsOnBrowserContextForTest(&profile);
 
   GURL url("http://a/");
   MockBackgroundContents* contents = new MockBackgroundContents(&profile);
@@ -216,8 +213,6 @@ TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAddedAndClosed) {
 TEST_F(BackgroundContentsServiceTest, RestartBackgroundContents) {
   TestingProfile profile;
   BackgroundContentsService service(&profile, command_line_.get());
-  BackgroundContentsServiceFactory::GetInstance()
-      ->RegisterUserPrefsOnBrowserContextForTest(&profile);
 
   GURL url("http://a/");
   {
@@ -248,8 +243,6 @@ TEST_F(BackgroundContentsServiceTest, RestartBackgroundContents) {
 TEST_F(BackgroundContentsServiceTest, TestApplicationIDLinkage) {
   TestingProfile profile;
   BackgroundContentsService service(&profile, command_line_.get());
-  BackgroundContentsServiceFactory::GetInstance()
-      ->RegisterUserPrefsOnBrowserContextForTest(&profile);
 
   EXPECT_EQ(NULL, service.GetAppBackgroundContents("appid"));
   MockBackgroundContents* contents =