Use BrowserProcess URLLoaderFactory in BlocklistStateFetcher

This CL changes the URLLoaderFactory used by the BlocklistStateFetcher
to be the one provided by |g_browser_process|. It also removes
cookies from such requests, to avoid leakage of identifiers when
communicating with Safe Browsing. Going forward, the Safe Browsing
Network Context will only be used when the Safe Browsing cookie is
needed.

Bug: 1049833
Change-Id: Ie52d88b2a2353afa7c520917605b125e6ae73ad7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2337289Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795256}

chrome/browser/extensions/blocklist_state_fetcher.cc

@@ -11,6 +11,7 @@
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "chrome/common/safe_browsing/crx_info.pb.h"
 #include "components/safe_browsing/core/db/v4_protocol_manager_util.h"
+#include "components/safe_browsing/core/features.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/escape.h"
 #include "net/traffic_annotation/network_traffic_annotation.h"
@@ -48,8 +49,13 @@ void BlocklistStateFetcher::Request(const std::string& id,
     return;
 
   if (g_browser_process && g_browser_process->safe_browsing_service()) {
-    url_loader_factory_ =
-        g_browser_process->safe_browsing_service()->GetURLLoaderFactory();
+    if (base::FeatureList::IsEnabled(
+            safe_browsing::kSafeBrowsingRemoveCookies)) {
+      url_loader_factory_ = g_browser_process->shared_url_loader_factory();
+    } else {
+      url_loader_factory_ =
+          g_browser_process->safe_browsing_service()->GetURLLoaderFactory();
+    }
   }
 
   SendRequest(id);
@@ -99,6 +105,9 @@ void BlocklistStateFetcher::SendRequest(const std::string& id) {
   auto resource_request = std::make_unique<network::ResourceRequest>();
   resource_request->url = request_url;
   resource_request->method = "POST";
+  if (base::FeatureList::IsEnabled(safe_browsing::kSafeBrowsingRemoveCookies)) {
+    resource_request->credentials_mode = network::mojom::CredentialsMode::kOmit;
+  }
   std::unique_ptr<network::SimpleURLLoader> fetcher_ptr =
       network::SimpleURLLoader::Create(std::move(resource_request),
                                        traffic_annotation);