Remove unnecessary initialization code from test

This seems to be causing some tests to flake. Tests fail because page A
is not being cached which is strange (at that point in the test we
haven't done anything yet). So the theory is that the initialization
might have some pending tasks (note no RunLoop::RunUntilIdle) that might
interfere with the caching.

The initialization is not really needed (that is the default) so we can
just remove that line.

Bug: 1126494
Change-Id: I03e5f7238966ac346e484a9f7072f442aa917159
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2402939Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#806138}

chrome/browser/chrome_back_forward_cache_browsertest.cc

@@ -250,10 +250,6 @@ IN_PROC_BROWSER_TEST_F(ChromeBackForwardCacheBrowserTest,
   GURL url_a(https_server.GetURL("a.com", "/title1.html"));
   GURL url_b(https_server.GetURL("b.com", "/title1.html"));
 
-  HostContentSettingsMapFactory::GetForProfile(browser()->profile())
-      ->SetDefaultContentSetting(ContentSettingsType::GEOLOCATION,
-                                 ContentSetting::CONTENT_SETTING_ASK);
-
   // 1) Navigate to A.
   EXPECT_TRUE(NavigateToURL(web_contents(), url_a));
   content::RenderFrameHost* rfh_a = current_frame_host();