Update Context Client Visibility to use Scoped Pattern

cc/test/test_context_support.h

Index: cc/test/test_context_support.h
diff --git a/cc/test/test_context_support.h b/cc/test/test_context_support.h
index f2b58d641e98038a0e0f71c444d97882bc151558..6d162001063e1f10392039f26e1ab93dd5346af4 100644
--- a/cc/test/test_context_support.h
+++ b/cc/test/test_context_support.h
@@ -30,7 +30,7 @@ class TestContextSupport : public gpu::ContextSupport {
   void SignalSyncToken(const gpu::SyncToken& sync_token,
                        const base::Closure& callback) override;
   void SignalQuery(uint32_t query, const base::Closure& callback) override;
-  void SetAggressivelyFreeResources(bool aggressively_free_resources) override;
+  void TrimResources() override;
   void Swap() override;
   void PartialSwapBuffers(const gfx::Rect& sub_buffer) override;
   void CommitOverlayPlanes() override;
@@ -42,7 +42,9 @@ class TestContextSupport : public gpu::ContextSupport {
   uint64_t ShareGroupTracingGUID() const override;
   void SetErrorMessageCallback(
       const base::Callback<void(const char*, int32_t)>& callback) override;
-  void SetClientVisible(int client_id, bool is_visible) override;
+  std::unique_ptr<ScopedVisibility> ClientBecameVisible() override;
+  void ClientBecameNotVisible(
+      std::unique_ptr<ScopedVisibility> visibility) override;
   bool AnyClientsVisible() const override;
 
   void CallAllSyncPointCallbacks();
@@ -65,8 +67,8 @@ class TestContextSupport : public gpu::ContextSupport {
  private:
   std::vector<base::Closure> sync_point_callbacks_;
   ScheduleOverlayPlaneCallback schedule_overlay_plane_callback_;
-  bool out_of_order_callbacks_;
-  std::set<int> visible_clients_;
+  bool out_of_order_callbacks_ = false;
+  uint32_t num_visible_clients_ = 0;
 
   base::WeakPtrFactory<TestContextSupport> weak_ptr_factory_;