Revert of Remove ForceReclaimResources

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index f0afd404d9111b5ae23acbe1491fc6d2bcee724c..b2fd2e17215b8e00a617b949a2a20be090cd5e37 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -8409,7 +8409,8 @@
   auto compositor_frame_sink = base::MakeUnique<TestCompositorFrameSink>(
       context_provider, TestContextProvider::CreateWorker(), nullptr, nullptr,
       RendererSettings(), base::ThreadTaskRunnerHandle::Get().get(),
-      true /* synchronous_composite */);
+      true /* synchronous_composite */,
+      false /* force_disable_reclaim_resources */);
   compositor_frame_sink->SetClient(&test_client_);
 
   CreateHostImpl(DefaultSettings(), std::move(compositor_frame_sink));
@@ -11448,6 +11449,32 @@
   EXPECT_FALSE(host_impl_->use_gpu_rasterization());
 }
 
+// A mock output surface which lets us detect calls to ForceReclaimResources.
+class MockReclaimResourcesCompositorFrameSink : public FakeCompositorFrameSink {
+ public:
+  MockReclaimResourcesCompositorFrameSink()
+      : FakeCompositorFrameSink(TestContextProvider::Create(),
+                                TestContextProvider::CreateWorker()) {}
+
+  MOCK_METHOD0(ForceReclaimResources, void());
+};
+
+// Display::Draw (and the planned Display Scheduler) currently rely on resources
+// being reclaimed to block drawing between BeginCommit / Swap. This test
+// ensures that BeginCommit triggers ForceReclaimResources. See
+// crbug.com/489515.
+TEST_F(LayerTreeHostImplTest, BeginCommitReclaimsResources) {
+  auto compositor_frame_sink =
+      base::MakeUnique<MockReclaimResourcesCompositorFrameSink>();
+  // Hold an unowned pointer to the output surface to use for mock expectations.
+  MockReclaimResourcesCompositorFrameSink* mock_compositor_frame_sink =
+      compositor_frame_sink.get();
+
+  CreateHostImpl(DefaultSettings(), std::move(compositor_frame_sink));
+  EXPECT_CALL(*mock_compositor_frame_sink, ForceReclaimResources()).Times(1);
+  host_impl_->BeginCommit();
+}
+
 TEST_F(LayerTreeHostImplTest, UpdatePageScaleFactorOnActiveTree) {
   // Check page scale factor update in property trees when an update is made
   // on the active tree.