cc: Fix missing render surfaces with output requests

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 bb315e79d02c152d57cb9ecb4dc8d343eee4acd1..0a7f5ac111d53ebfbfcc3c2d8f522c636c64b2b3 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -6320,4 +6320,85 @@ class LayerTreeHostTestNoTasksBetweenWillAndDidCommit
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestNoTasksBetweenWillAndDidCommit);
 
+// Verify that if a LayerImpl holds onto a copy request for multiple
+// frames that it will continue to have a render surface through
+// multiple commits, even though the Layer itself has no reason
+// to have a render surface.
+class LayerPreserveRenderSurfaceFromOutputRequests : public LayerTreeHostTest {
+ protected:
+  void SetupTree() override {
+    scoped_refptr<Layer> root = Layer::Create();
+    root->CreateRenderSurface();
+    root->SetBounds(gfx::Size(10, 10));
+    child_ = Layer::Create();
+    child_->SetBounds(gfx::Size(20, 20));
+    root->AddChild(child_);
+
+    layer_tree_host()->SetRootLayer(root);
+    LayerTreeHostTest::SetupTree();
+  }
+
+  static void CopyOutputCallback(scoped_ptr<CopyOutputResult> result) {}
+
+  void BeginTest() override {
+    child_->RequestCopyOfOutput(
+        CopyOutputRequest::CreateBitmapRequest(base::Bind(CopyOutputCallback)));
+    EXPECT_TRUE(child_->HasCopyRequest());
+    PostSetNeedsCommitToMainThread();
+  }
+
+  void DidCommit() override { EXPECT_FALSE(child_->HasCopyRequest()); }
+
+  void CommitCompleteOnThread(LayerTreeHostImpl* host_impl) override {
+    LayerImpl* child_impl = host_impl->sync_tree()->LayerById(child_->id());
+    ASSERT_TRUE(child_impl);

[danakj, 2015/02/19 18:08:39]

ASSERT_ in layer tree tests is marginally bleh cuz it just makes the test time
out instead of end immediately with a crash

[enne (OOO), 2015/02/19 18:10:31]

But crashing in a unit test ends everything?

[danakj, 2015/02/19 18:36:44]

Not sure what you mean, it ends the test immediately but not other tests (with
test launcher)?

[enne (OOO), 2015/02/19 18:40:33]

Ok.  Removed asserts.

+
+    switch (host_impl->sync_tree()->source_frame_number()) {
+      case 0:
+        EXPECT_TRUE(child_impl->HasCopyRequest());
+        EXPECT_TRUE(child_impl->render_surface());
+        break;
+      case 1:
+        if (host_impl->proxy()->CommitToActiveTree()) {
+          EXPECT_TRUE(child_impl->HasCopyRequest());
+          EXPECT_TRUE(child_impl->render_surface());
+        } else {
+          EXPECT_FALSE(child_impl->HasCopyRequest());
+          EXPECT_FALSE(child_impl->render_surface());
+        }
+        break;
+      default:
+        NOTREACHED();
+        break;
+    }
+  }
+
+  void DidActivateTreeOnThread(LayerTreeHostImpl* host_impl) override {
+    LayerImpl* child_impl = host_impl->active_tree()->LayerById(child_->id());
+    ASSERT_TRUE(child_impl);
+    EXPECT_TRUE(child_impl->HasCopyRequest());
+    EXPECT_TRUE(child_impl->render_surface());
+
+    switch (host_impl->active_tree()->source_frame_number()) {
+      case 0:
+        // Lose output surface to prevent drawing and cause another commit.
+        host_impl->DidLoseOutputSurface();
+        break;
+      case 1:
+        EndTest();
+        break;
+      default:
+        NOTREACHED();
+        break;
+    }
+  }
+
+  void AfterTest() override {}
+
+ private:
+  scoped_refptr<Layer> child_;
+};
+
+SINGLE_AND_MULTI_THREAD_TEST_F(LayerPreserveRenderSurfaceFromOutputRequests);
+
 }  // namespace cc