Clean up unused ResourceLoadingHintsBrowserTest test suites

This CL fixes the following warnings when running browser_tests:
UninstantiatedParamaterizedTestSuite<ResourceLoadingHintsBrowserTestWithExperimentEnabled>
UninstantiatedParamaterizedTestSuite<ResourceLoadingHintsBrowserTestWithExperimentDisabled>

These tests were removed in:
https://chromium-review.googlesource.com/c/chromium/src/+/2316835

Bug: 1045846
Change-Id: I1368bbb925ae8c213d2ba3a0bfed724e894cc6e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2331251
Commit-Queue: Sophie Chang <sophiechang@chromium.org>
Reviewed-by: Sophie Chang <sophiechang@chromium.org>
Auto-Submit: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#793504}

chrome/browser/previews/resource_loading_hints/resource_loading_hints_browsertest.cc

@@ -464,45 +464,6 @@ INSTANTIATE_TEST_SUITE_P(All,
                          ::testing::Values(REGULAR_PAGE, PRELOAD_PAGE));
 
 
-class ResourceLoadingHintsBrowserTestWithExperimentEnabled
-    : public ResourceLoadingHintsBrowserTest {
- public:
-  void InitExtraFeatures() override {
-    feature_list_.InitAndEnableFeatureWithParameters(
-        optimization_guide::features::kOptimizationHintsExperiments,
-        {{optimization_guide::features::kOptimizationHintsExperimentNameParam,
-          optimization_guide::testing::kFooExperimentName}});
-  }
-
- private:
-  base::test::ScopedFeatureList feature_list_;
-};
-
-// First parameter determines the test webpage that should be used.
-INSTANTIATE_TEST_SUITE_P(All,
-                         ResourceLoadingHintsBrowserTestWithExperimentEnabled,
-                         ::testing::Values(REGULAR_PAGE, PRELOAD_PAGE));
-
-
-class ResourceLoadingHintsBrowserTestWithExperimentDisabled
-    : public ResourceLoadingHintsBrowserTest {
- public:
-  void InitExtraFeatures() override {
-    feature_list_.InitAndEnableFeatureWithParameters(
-        optimization_guide::features::kOptimizationHintsExperiments,
-        {{optimization_guide::features::kOptimizationHintsExperimentNameParam,
-          "some_other_experiment"}});
-  }
-
- private:
-  base::test::ScopedFeatureList feature_list_;
-};
-
-// First parameter determines the test webpage that should be used.
-INSTANTIATE_TEST_SUITE_P(All,
-                         ResourceLoadingHintsBrowserTestWithExperimentDisabled,
-                         ::testing::Values(REGULAR_PAGE, PRELOAD_PAGE));
-
 IN_PROC_BROWSER_TEST_P(
     ResourceLoadingHintsBrowserTest,
     DISABLE_ON_WIN_MAC_CHROMEOS(