exo: Add a test for crrev.com/c/1379273

Add a test to make sure that already removed presentation callbacks for
submitted compositor frames do not cause crashes.

BUG=915458

Change-Id: Ia0ae709a6a6792564a01d3086369f32850cf14fb
Reviewed-on: https://chromium-review.googlesource.com/c/1381778
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618373}

components/exo/pointer_unittest.cc

@@ -285,6 +285,7 @@ TEST_F(MAYBE_PointerTest, SetCursorAndSetCursorType) {
 
   // Set pointer surface.
   pointer->SetCursor(pointer_surface.get(), gfx::Point());
+  EXPECT_EQ(1u, pointer->GetActivePresentationCallbacksForTesting().size());
   base::RunLoop().RunUntilIdle();
 
   {
@@ -299,12 +300,22 @@ TEST_F(MAYBE_PointerTest, SetCursorAndSetCursorType) {
 
   // Set the cursor type to the kNone through SetCursorType.
   pointer->SetCursorType(ui::CursorType::kNone);
+  EXPECT_TRUE(pointer->GetActivePresentationCallbacksForTesting().empty());
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(nullptr, pointer->root_surface());
 
   // Set the same pointer surface again.
   pointer->SetCursor(pointer_surface.get(), gfx::Point());
-  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1u, pointer->GetActivePresentationCallbacksForTesting().size());
+  auto& list =
+      pointer->GetActivePresentationCallbacksForTesting().begin()->second;
+  base::RunLoop runloop;
+  list.push_back(base::BindRepeating(
+      [](base::Closure callback, const gfx::PresentationFeedback&) {
+        callback.Run();
+      },
+      runloop.QuitClosure()));
+  runloop.Run();
 
   {
     viz::SurfaceId surface_id = pointer->host_window()->GetSurfaceId();

components/exo/surface_tree_host.h

@@ -65,6 +65,12 @@ class SurfaceTreeHost : public SurfaceDelegate,
     return layer_tree_frame_sink_holder_.get();
   }
 
+  using PresentationCallbacks = std::list<Surface::PresentationCallback>;
+  base::flat_map<uint32_t, PresentationCallbacks>&
+  GetActivePresentationCallbacksForTesting() {
+    return active_presentation_callbacks_;
+  }
+
   // Overridden from SurfaceDelegate:
   void OnSurfaceCommit() override;
   bool IsSurfaceSynchronized() const override;
@@ -104,7 +110,6 @@ class SurfaceTreeHost : public SurfaceDelegate,
 
   // These lists contains the callbacks to notify the client when surface
   // contents have been presented.
-  using PresentationCallbacks = std::list<Surface::PresentationCallback>;
   PresentationCallbacks presentation_callbacks_;
   base::flat_map<uint32_t, PresentationCallbacks>
       active_presentation_callbacks_;