cc: Setup API to release OutputSurface from LTHClient.

cc/trees/layer_tree_host_unittest_context.cc

Index: cc/trees/layer_tree_host_unittest_context.cc
diff --git a/cc/trees/layer_tree_host_unittest_context.cc b/cc/trees/layer_tree_host_unittest_context.cc
index 7c766fe8bedc60376fafb543e8f51667e2c40682..47481b7605770c5a062cbb2309a851884e3a28a8 100644
--- a/cc/trees/layer_tree_host_unittest_context.cc
+++ b/cc/trees/layer_tree_host_unittest_context.cc
@@ -382,6 +382,61 @@ class LayerTreeHostClientNotReadyDoesNotCreateOutputSurface
 SINGLE_AND_MULTI_THREAD_TEST_F(
     LayerTreeHostClientNotReadyDoesNotCreateOutputSurface);
 
+class LayerTreeHostClientTakeAwayOutputSurface
+    : public LayerTreeHostContextTest {
+ public:
+  LayerTreeHostClientTakeAwayOutputSurface() : LayerTreeHostContextTest() {
+    setos_counter = 0;
+  }
+
+  void BeginTest() override { PostSetNeedsCommitToMainThread(); }
+
+  void RequestNewOutputSurface() override { CreateAndSetOutputSurface(); }
+
+  void CreateAndSetOutputSurface() {
+    scoped_ptr<OutputSurface> surface =
+        LayerTreeHostContextTest::CreateOutputSurface();
+    CHECK(surface);
+    layer_tree_host()->SetOutputSurface(surface.Pass());
+    setos_counter++;
+  }
+
+  void HideAndReleaseOutputSurface() {
+    EXPECT_TRUE(layer_tree_host()->proxy()->IsMainThread());
+    layer_tree_host()->SetVisible(false);
+    scoped_ptr<OutputSurface> surface =
+        layer_tree_host()->ReleaseOutputSurface();
+    CHECK(surface);
+    MainThreadTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(&LayerTreeHostClientTakeAwayOutputSurface::MakeVisible,
+                   base::Unretained(this)));
+  }
+
+  void DidInitializeOutputSurface() override {
+    if (setos_counter == 0) {
+      EXPECT_TRUE(layer_tree_host()->visible());

[no sievers, 2015/09/10 17:27:45]

I think the reason that you were not able to move this check outside of the
if-statement is that you didn't make the change to the scheduler state machine
and it now immediately asks you for a new OutputSurface after you release it. We
can pull the behavioral change into a separate patch though (that's probably
better since otherwise the patch doesn't change existing behavior in use), but
then you should change the test to not call CreateAndSetOutputSurface() the
second time until after we made the LTH visible again.

[sohanjg, 2015/09/11 07:00:50]

Done.

+      MainThreadTaskRunner()->PostTask(
+          FROM_HERE, base::Bind(&LayerTreeHostClientTakeAwayOutputSurface::
+                                    HideAndReleaseOutputSurface,
+                                base::Unretained(this)));
+    } else {
+      EndTest();
+    }
+  }
+
+  void MakeVisible() {
+    EXPECT_TRUE(layer_tree_host()->proxy()->IsMainThread());
+    layer_tree_host()->SetVisible(true);
+  }
+
+  void AfterTest() override {}
+
+  int setos_counter;
+};
+
+SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostClientTakeAwayOutputSurface);
+
 class MultipleCompositeDoesNotCreateOutputSurface
     : public LayerTreeHostContextTest {
  public: