Instantiate ScopedTaskEnvironment in net unittests.

net/url_request/url_request_data_job_fuzzer.cc

Index: net/url_request/url_request_data_job_fuzzer.cc
diff --git a/net/url_request/url_request_data_job_fuzzer.cc b/net/url_request/url_request_data_job_fuzzer.cc
index d996079dcb4cd5a1322a7450ab5148383ddfbd30..dee66d08597af2e9e07a433b349aad30fa251adc 100644
--- a/net/url_request/url_request_data_job_fuzzer.cc
+++ b/net/url_request/url_request_data_job_fuzzer.cc
@@ -7,7 +7,6 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/memory/singleton.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/test/fuzzed_data_provider.h"
 #include "base/test/scoped_task_scheduler.h"
@@ -32,9 +31,7 @@ const size_t kMaxLengthForFuzzedRange = 32;
 class URLRequestDataJobFuzzerHarness : public net::URLRequest::Delegate {
  public:
   URLRequestDataJobFuzzerHarness()
-      : scoped_task_scheduler_(base::MessageLoop::current()),
-        task_runner_(base::ThreadTaskRunnerHandle::Get()),
-        context_(true) {
+      : task_runner_(base::ThreadTaskRunnerHandle::Get()), context_(true) {
     job_factory_.SetProtocolHandler(
         "data", base::MakeUnique<net::DataProtocolHandler>());
     context_.set_job_factory(&job_factory_);
@@ -160,7 +157,6 @@ class URLRequestDataJobFuzzerHarness : public net::URLRequest::Delegate {
  private:
   friend struct base::DefaultSingletonTraits<URLRequestDataJobFuzzerHarness>;
 
-  base::test::ScopedTaskScheduler scoped_task_scheduler_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   net::TestURLRequestContext context_;