Have ResourceLoader use FetchContext::CreateURLLoader

third_party/WebKit/Source/platform/loader/testing/MockFetchContext.h

Index: third_party/WebKit/Source/platform/loader/testing/MockFetchContext.h
diff --git a/third_party/WebKit/Source/platform/loader/testing/MockFetchContext.h b/third_party/WebKit/Source/platform/loader/testing/MockFetchContext.h
index 1e92508dad413ec2426d7e184c7913ef25959fd7..f1b9ccb82111b97df0438dd448af525eee0b1e89 100644
--- a/third_party/WebKit/Source/platform/loader/testing/MockFetchContext.h
+++ b/third_party/WebKit/Source/platform/loader/testing/MockFetchContext.h
@@ -10,6 +10,7 @@
 #include "platform/loader/fetch/ResourceTimingInfo.h"
 #include "platform/scheduler/test/fake_web_task_runner.h"
 #include "platform/wtf/PtrUtil.h"
+#include "public/platform/Platform.h"
 
 #include <memory>
 
@@ -74,6 +75,10 @@ class MockFetchContext : public FetchContext {
     transfer_size_ = resource_timing_info.TransferSize();
   }
 
+  std::unique_ptr<WebURLLoader> CreateURLLoader() override {
+    return Platform::Current()->CreateURLLoader();
+  }
+
  private:
   MockFetchContext(LoadPolicy load_policy, RefPtr<WebTaskRunner> task_runner)
       : load_policy_(load_policy),