Remove unneeded ContentBrowserClient stub in unit tests

This removes the stub implementation of WillCreateURLLoaderFactory in
unit_tests, which was needed when interceptors ran on the IO thread.

Bug: 966633
Change-Id: I2305606c0f178e98661ca70eb1696ce5200ab445
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1860885Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706088}

chrome/test/base/chrome_unit_test_suite.cc

@@ -50,21 +50,6 @@ class ChromeContentBrowserClientWithoutNetworkServiceInitialization
   // Skip some production Network Service code that doesn't work in unit tests.
   void OnNetworkServiceCreated(
       network::mojom::NetworkService* network_service) override {}
-  // Overridden to skip a call to ProfileIOData::FromResourceContext downstream
-  // of ProxyingURLLoaderFactory, which assumes the ResourceContext is a
-  // ProfileIOData::ResourceContext, but in unit tests it's a mock.
-  bool WillCreateURLLoaderFactory(
-      content::BrowserContext* browser_context,
-      content::RenderFrameHost* frame,
-      int render_process_id,
-      URLLoaderFactoryType type,
-      const url::Origin& request_initiator,
-      mojo::PendingReceiver<network::mojom::URLLoaderFactory>* factory_receiver,
-      mojo::PendingRemote<network::mojom::TrustedURLLoaderHeaderClient>*
-          header_client,
-      bool* bypass_redirect_checks) override {
-    return false;
-  }
 };
 
 // Creates a TestingBrowserProcess for each test.