Make touch events uncancelable during fling when they are on the current active scroll layer

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 f2702a30d84dc2cfe4923d137fb62333cb0415db..23f4169d7384b3715e5bb01fad0bd234c829704c 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -808,7 +808,8 @@ TEST_F(LayerTreeHostImplTest, ScrollBlocksOnTouchEventHandlers) {
 
   // Touch handler regions determine whether touch events block scroll.
   root->SetTouchEventHandlerRegion(gfx::Rect(0, 0, 100, 100));
-  EXPECT_TRUE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 10)));
+  EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(10, 10)),
+            EventListenerProperties::kBlocking);
 
   // But they don't influence the actual handling of the scroll gestures.
   InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
@@ -818,11 +819,14 @@ TEST_F(LayerTreeHostImplTest, ScrollBlocksOnTouchEventHandlers) {
             status.main_thread_scrolling_reasons);
   host_impl_->ScrollEnd(EndState().get());
 
-  EXPECT_TRUE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 30)));
+  EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(10, 30)),
+            EventListenerProperties::kBlocking);
   root->SetTouchEventHandlerRegion(gfx::Rect());
-  EXPECT_FALSE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 30)));
+  EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(10, 30)),
+            EventListenerProperties::kNone);
   child->SetTouchEventHandlerRegion(gfx::Rect(0, 0, 50, 50));
-  EXPECT_TRUE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 30)));
+  EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(10, 30)),
+            EventListenerProperties::kBlocking);
 }
 
 TEST_F(LayerTreeHostImplTest, FlingOnlyWhenScrollingTouchscreen) {
@@ -9928,6 +9932,79 @@ TEST_F(LayerTreeHostImplTest, OnDrawConstraintSetNeedsRedraw) {
   EXPECT_FALSE(last_on_draw_frame_->has_no_damage);
 }
 
+TEST_F(LayerTreeHostImplTest, TouchInsideOrOutsideFlingLayer) {
+  gfx::Size surface_size(100, 100);
+  gfx::Size inner_size(50, 50);

[bokan, 2016/11/15 22:42:40]

Please use CreateBasicVirtualViewportLayers to initialize the layer tree. It
makes sure we're everything is properly initialized to look and behave like the
compositor does when Chrome is running in the wild. For an example, see:

TEST_F(LayerTreeHostImplTest, ScrollChildBeyondLimit)

Then you can add your child/grand-child layers and avoid a lot of boilerplate.

[lanwei, 2016/11/16 21:13:28]

Done.

+  std::unique_ptr<LayerImpl> root =
+      LayerImpl::Create(host_impl_->active_tree(), 1);
+  root->test_properties()->force_render_surface = true;
+
+  std::unique_ptr<LayerImpl> root_scrolling_layer =
+      CreateScrollableLayer(2, surface_size, root.get());
+  auto* root_scrolling = root_scrolling_layer.get();
+  root->test_properties()->AddChild(std::move(root_scrolling_layer));
+
+  std::unique_ptr<LayerImpl> child_layer =
+      CreateScrollableLayer(3, surface_size, root.get());
+  auto* child = child_layer.get();
+  root_scrolling->test_properties()->AddChild(std::move(child_layer));
+
+  std::unique_ptr<LayerImpl> grand_child_layer =
+      CreateScrollableLayer(4, inner_size, root.get());
+  child->test_properties()->AddChild(std::move(grand_child_layer));
+
+  host_impl_->active_tree()->SetRootLayerForTesting(std::move(root));
+  host_impl_->active_tree()->BuildPropertyTreesForTesting();
+  host_impl_->active_tree()->DidBecomeActive();
+
+  host_impl_->SetViewportSize(surface_size);
+  DrawFrame();
+  {
+    std::unique_ptr<ScrollAndScaleSet> scroll_info;
+    LayerImpl* child = host_impl_->active_tree()

[bokan, 2016/11/15 22:42:40]

We've already saved the child and grand_child pointers above, no need to get
them again.

[lanwei, 2016/11/16 21:13:28]

Done.

+                           ->root_layer_for_testing()
+                           ->test_properties()
+                           ->children[0]
+                           ->test_properties()
+                           ->children[0];
+    LayerImpl* grand_child = child->test_properties()->children[0];
+    child->SetTouchEventHandlerRegion(gfx::Rect(0, 0, 100, 100));
+    grand_child->SetTouchEventHandlerRegion(gfx::Rect(0, 0, 100, 100));
+    EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(10, 10)),
+              EventListenerProperties::kBlocking);
+    // Flinging the child layer.
+    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
+              host_impl_
+                  ->ScrollBegin(BeginState(gfx::Point(60, 60)).get(),
+                                InputHandler::TOUCHSCREEN)
+                  .thread);
+    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
+              host_impl_->FlingScrollBegin().thread);
+    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child);
+    // Touch on the child layer, which is an active fling layer, the touch
+    // event handler will force to be passive.
+    EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(70, 80)),
+              EventListenerProperties::kBlockingAndPassiveDueToFling);
+    // Touch on the grand child layer, which is a descendant of an active fling
+    // layer, the touch event handler will force to be passive.
+    EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(20, 30)),
+              EventListenerProperties::kBlockingAndPassiveDueToFling);
+
+    // Now flinging on the grand child layer.
+    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
+              host_impl_
+                  ->ScrollBegin(BeginState(gfx::Point(10, 10)).get(),
+                                InputHandler::TOUCHSCREEN)
+                  .thread);
+    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
+              host_impl_->FlingScrollBegin().thread);
+    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
+    // Touch on the child layer, the touch event handler will still be blocking.
+    EXPECT_EQ(host_impl_->DoTouchHandlersBlockScrollAt(gfx::Point(60, 60)),
+              EventListenerProperties::kBlocking);
+  }
+}
+
 class ResourcelessSoftwareLayerTreeHostImplTest : public LayerTreeHostImplTest {
  protected:
   std::unique_ptr<CompositorFrameSink> CreateCompositorFrameSink() override {