Move scopedfeaturelist init to test constructor

This CL is deceptively large to ensure that test cases with the same
feature flags are somewhat colocated.

Bug: 1035004
Change-Id: Ia09794fab81801269920d0e2403adb5a49e97d65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1974750
Commit-Queue: Sophie Chang <sophiechang@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726139}

chrome/browser/optimization_guide/optimization_guide_hints_manager.h

@@ -144,15 +144,15 @@ class OptimizationGuideHintsManager
 
  private:
   FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerTest, IsGoogleURL);
-  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerTest,
+  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerFetchingTest,
                            HintsFetched_AtSRP_ECT_SLOW_2G);
-  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerTest,
+  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerFetchingTest,
                            HintsFetched_AtSRP_ECT_4G);
-  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerTest,
+  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerFetchingTest,
                            HintsFetched_AtNonSRP_ECT_SLOW_2G);
-  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerTest,
+  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerFetchingTest,
                            HintsFetched_AtSRP_ECT_SLOW_2G_DuplicatesRemoved);
-  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerTest,
+  FRIEND_TEST_ALL_PREFIXES(OptimizationGuideHintsManagerFetchingTest,
                            HintsFetched_AtSRP_ECT_SLOW_2G_InsecureHostsRemoved);
   // Processes the hints component.
   //