[privacy_budget] Simple rename.

InspectableIdentifiabilityStudy{Settings => State}

Bug: 1100424
Bug: 973801
Change-Id: I37c8840146ec7f3868d0f2c4115f74e18565947c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2279924
Auto-Submit: Asanka Herath <asanka@chromium.org>
Commit-Queue: Maksim Orlovich <morlovich@chromium.org>
Reviewed-by: Maksim Orlovich <morlovich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#785719}

chrome/browser/privacy_budget/identifiability_study_state.h

@@ -16,7 +16,7 @@
 #include "third_party/blink/public/common/privacy_budget/identifiable_surface.h"
 
 namespace test_utils {
-class InspectableIdentifiabilityStudySettings;
+class InspectableIdentifiabilityStudyState;
 }  // namespace test_utils
 
 // Current state of the identifiability study.
@@ -85,7 +85,7 @@ class IdentifiabilityStudyState {
   static constexpr int kGeneratorVersion = 1;
 
  private:
-  friend class test_utils::InspectableIdentifiabilityStudySettings;
+  friend class test_utils::InspectableIdentifiabilityStudyState;
 
   using IdentifiableSurfaceSet =
       PrivacyBudgetSettingsProvider::IdentifiableSurfaceSet;