Update Context Client Visibility to use Scoped Pattern

cc/trees/layer_tree_host_unittest.cc

Index: cc/trees/layer_tree_host_unittest.cc
diff --git a/cc/trees/layer_tree_host_unittest.cc b/cc/trees/layer_tree_host_unittest.cc
index 4efbb6872ae2a022a31671e0b71ae87a8d660eab..5f212536f20798faa8c3b0b2c0eb6bd074dd9a84 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -450,13 +450,13 @@ class LayerTreeHostFreeWorkerContextResourcesTest : public LayerTreeHostTest {
     // Ensure that our mock calls execute in sequence.
     ::testing::InSequence s;
 
-    // At init, visibility is set to true and we will call
-    // SetAggressivelyFreeResources(false).
-    EXPECT_CALL(*mock_context_support_ptr_, SetClientVisible(0, true));
+    // At init, visibility is set to true.
+    EXPECT_CALL(*mock_context_support_ptr_, ClientBecameVisible())
+        .WillOnce(
+            ::testing::Invoke(mock_context_support_ptr_,
+                              &MockContextSupport::SuperClientBecameVisible));
     EXPECT_CALL(*mock_context_support_ptr_, AnyClientsVisible())
         .WillOnce(::testing::Return(true));
-    EXPECT_CALL(*mock_context_support_ptr_,
-                SetAggressivelyFreeResources(false));
 
     return LayerTreeHostTest::CreateDelegatingOutputSurface(
         std::move(compositor_context_provider),
@@ -478,13 +478,15 @@ class LayerTreeHostFreeWorkerContextResourcesTest : public LayerTreeHostTest {
     ::testing::InSequence s;
 
     // While running, visibility is set to false, and we will call
-    // DeleteCachedResources and SetAggressivelyFreeResources(true).
-    EXPECT_CALL(*mock_context_support_ptr_, SetClientVisible(0, false));
+    // DeleteCachedResources.
+    EXPECT_CALL(*mock_context_support_ptr_, ClientBecameNotVisible_(_))
+        .WillOnce(::testing::Invoke(
+            mock_context_support_ptr_,
+            &MockContextSupport::SuperClientBecameNotVisible));
     EXPECT_CALL(*mock_context_support_ptr_, AnyClientsVisible())
         .WillOnce(::testing::Return(false));
-    EXPECT_CALL(*mock_context_provider_ptr_, DeleteCachedResources());
-    EXPECT_CALL(*mock_context_support_ptr_, SetAggressivelyFreeResources(true))
-        .WillOnce(testing::Invoke([this](bool is_visible) { EndTest(); }));
+    EXPECT_CALL(*mock_context_provider_ptr_, DeleteCachedResources())
+        .WillOnce(testing::Invoke([this]() { EndTest(); }));
   }
 
   void AfterTest() override {
@@ -509,11 +511,25 @@ class LayerTreeHostFreeWorkerContextResourcesTest : public LayerTreeHostTest {
 
   class MockContextSupport : public TestContextSupport {
    public:
+    using VisibilityToken = std::unique_ptr<ScopedVisibility>;
     MockContextSupport() {}
-    MOCK_METHOD1(SetAggressivelyFreeResources,
-                 void(bool aggressively_free_resources));
-    MOCK_METHOD2(SetClientVisible, void(int client_id, bool is_visible));
+    MOCK_METHOD0(ClientBecameVisible, VisibilityToken());
+    MOCK_METHOD1(ClientBecameNotVisible_,
+                 void(VisibilityToken& visibility));  // NOLINT
     MOCK_CONST_METHOD0(AnyClientsVisible, bool());
+
+    // Wrapper to allow mocking w/ move-only type.
+    void ClientBecameNotVisible(VisibilityToken visibility) override {
+      ClientBecameNotVisible_(visibility);
+    }
+
+    // Wrappers to allow forwarding to super class implementation.
+    void SuperClientBecameNotVisible(VisibilityToken& visibility) {  // NOLINT
+      TestContextSupport::ClientBecameNotVisible(std::move(visibility));
+    }
+    VisibilityToken SuperClientBecameVisible() {
+      return TestContextSupport::ClientBecameVisible();
+    }
   };
 
   MockContextSupport* mock_context_support_ptr_;